Recombinant Proteins

A soluble, single-chain Kd molecule produced by yeast selects a peptide repertoire indistinguishable from that of cell-surface-associated Kd Peptide binding to a soluble, single-chain Kd protein produced by the yeast strain Kfuyverumyces lactis, and to Kd molecules on Kd-expressing cells (P815) was studied using radiolabeled Kd-restricted peptides. The stability of the peptide-Kd complexes formed was monitored in the absence and presence of unlabeled competitor peptides. Radioiodination of the Tyr anchor residue in position 2 of the peptide interferes with binding. A Kd-biased peptide library apd a modified antigenic peptide in which a second Tyr was added in positions 6 and 8, respectively, were therefore used to assay binding. Recombinant and cellassociated Kd molecules are very similar in the following respects: the ease with which the proteins can be loaded with labeled peptide; the spectrum of peptides selected from a peptide library; the stability of the labeled peptide-Kd complex formed; and the ability to partially dissociate the class I-peptide complex with exogenous, unlabeled peptides. These results imply that measurements of peptide binding to soluble Kd molecules are a reliable indicator of the peptide-binding properties of Kd proteins on living cells. The large quantities of soluble recombinant Kd protein currently available represent an invaluable tool not only for dissecting the molecular mechanisms of antigen presentation but also for vaccinations and the design of T cell-specific toxins.

Interactions between the leukocyte adhesion receptor L-selectin and P-selectin glycoprotein ligand-1 play an important role in regulating the inflammatory response by mediating leukocyte tethering and rolling on adherent leukocytes. In this study, we have examined the effect of post-translational modifications of PSGL-1 including Tyr sulfation and presentation of sialylated and fucosylated O-glycans for L-selectin binding. The functional importance of these modifications was determined by analyzing soluble L-selectin binding and leukocyte rolling on CHO cells expressing various glycoforms of PSGL-1 or mutant PSGL-1 targeted at Nterminal Thr or Tyr residues. Simultaneous expression of core-2 ␤1,6-N-acetylglucosaminyltransferase and fucosyltransferase VII was required for optimal L-selectin binding to PSGL-1. Substitution of Thr-57 by Ala but not of Thr-44, strongly decreased L-selectin binding and leukocyte rolling on PSGL-1. Substitution of Tyr by Phe revealed that PSGL-1 Tyr-51 plays a predominant role in mediating L-selectin binding and leukocyte rolling whereas Tyr-48 has a minor role, an observation that contrasts with the pattern seen for the interactions between PSGL-1 and P-selectin where Tyr-48 plays a key role. Molecular modeling analysis of L-selectin and Pselectin interactions with PSGL-1 further supported these observations. Additional experiments showed that core-2 O-glycans attached to Thr-57 were also of critical importance in regulating the velocity and stability of leukocyte rolling. These observations pinpoint the structural characteristics of PSGL-1 that are required for optimal interactions with L-selectin and may be responsible for the specific kinetic and mechanical bond properties of the L-selectin-PSGL-1 adhesion receptorcounterreceptor pair.

Evolutionary pressure has selected antibodies as key immune molecules acting against foreign pathogens. The development of monoclonal antibody technology has allowed their widespread use in research, real-time diagnosis and treatment of multiple diseases, including cancer. However, compared with hematologic malignancies, solid tumors have often proven to be relatively resistant to antibody-based therapies. In an attempt to improve the tumor-targeting efficacy of antibodies, new formats with modified, multivalent properties have been generated. Initially, these formats imitated the structure of native IgG, creating mostly monospecific, bivalent antibodies. Recently, novel trivalent antibodies have been developed to maximize tumor targeting capabilities through enhanced biodistribution and functional affinity. We review recent advances in the engineering of multivalent antibodies and further discuss their promise as agents for in vivo diagnostics and therapy.

Phytase production using Escherichia coli BL21 (DE3), a recombinant strain harboring a plasmid encoding thermostable Bacillus phytase, in semi-industrial scale was studied in this work. Among the factors needed to be considered in order to achieve high enzyme yield, aeration rate plays an important role. Suitable aeration is required to
supply cells with sufficient amount of air for cell and phytase production. The effect of different aeration rates, (1.0, 2.0 and 3.0 vv-1min-1), on the kinetics of cell growth and phytase production by the recombinant E. coli BL21 (DE3) in 16-L pilot scale stirred tank bioreactor was investigated. The highest cell concentration of 3.81 gL-1 concomitant with the maximal total phytase production of 15.63 UmL-1 were obtained in a bioreactor of aeration rate 3.0vv-1min-1. At this high aeration rate, a maximal specific growth rate (μmax) and the maximal specific phytase production of 0.33 h-1 and 4102Ug-1, respectively, were achieved.

Objective: Young adults with childhood-onset GH deficiency (GHD) have reduced memory and attention, which can be improved by treatment with GH. Little information is available on cognitive function in elderly GHD patients. Design: Single center, double-blind, randomized, placebo-controlled study of 52-week duration. Methods: Elderly GH therapy naïve GHD patients (nZ34; age range 60-77 years) were enrolled and randomized to receive placebo or GH therapy which was titrated to achieve a target IGF-I level of C1 to C2 S.D. of the normal mean for age. Cognitive function was assessed at baseline and after 24 and 52 weeks, using a computerized psychometric test package (Neurobehavioral Examination System-2). Results: The mean GH dose was 0.16G0.06 mg/day; mean IGF-I increased from 135G59 ng/ml at baseline to 213G77 ng/ml during active treatment. The GH-treated group had better mean serial digit learning scores compared with placebo group (P!0.05). Assessment of effect sizes showed that improvements in memory occurred with GH after 24 weeks. The overall adverse event rates were similar in the GH and the placebo group. Conclusion: This study indicates that GH replacement may be accompanied by improvement in certain measures of cognitive function in elderly patients with GHD.

Context: Recombinant human GH (rhGH) is prescribed for the treatment of adults with GH deficiency (GHD). However, conflicting data are available on the efficacy of rhGH treatment in elderly GHD patients. Objective: To assess the efficacy of rhGH treatment in elderly GHD subjects. Methods: We searched the available literature in PubMed, Cochrane Library, Web of Science and EMBASE. Study selection: Studies on GHD patients, aged O60 years, treated with rhGH were eligible for inclusion. Data extraction was performed by two reviewers independently. Results: We found 11 eligible studies with a total of 534 patients. Only two studies had prospective, randomized, placebo-controlled study designs of rhGH treatment with a duration of 6 (nZ15) and 12 months (nZ62), respectively. Treatment with rhGH decreased total and low density lipoprotein (LDL) cholesterol levels by 4-8 and 11-16%, respectively, but did not alter high density lipoprotein or triglyceride levels. RhGH did not affect body mass index, but decreased waist circumference (by w3 cm) and waist/hip ratio. RhGh did not consistently affect blood pressure or bone mineral density. RhGH increased lean body mass by 2-5% and decreased total fat mass by 7-10% in four studies, but did not affect body composition in two other studies. RhGH consistently improved quality of life (QoL) parameters reflected in AGHDA-scores. There were no explicit data on elderly GHD patients aged O80 years. Conclusion: RhGH replacement in elderly subjects with GHD decreases LDL cholesterol levels and improves QoL, but the effects on other parameters are not unequivocal. There were no data on the efficacy and safety of rhGH treatment in octogenarians with GHD.

Flexibility of intrinsically disordered tau protein is important for performing its functions. It is believed that alteration of the flexibility is instrumental to the assembly of tau protein into paired helical filaments (PHF) in tauopathies. Tau flexibility represents the main obstacle for structure determination of its conformation in physiology and/or pathology. We have alleviated this inherited difficulty by using specific monoclonal antibodies as tau protein surrogate binding partners. In this work we compare two ''antibody mold structures": (1) X-ray structure of the free form of the Alzheimer's disease PHF core-specific antibody MN423 and (2) previously solved structure of the complex of MN423 with the PHF core C-terminal tau peptide. We found that MN423 combining site is in both structures identical. As a consequence, recombinant tau assumes in the complex a fold determined by the antibody combining site. Obtained results show that MN423 functions as a molecular mold for the PHF core segment, and opens the way for structure determination of other PHF core segments providing that other conformation-specific antibodies are available. Data from in silico docking of tau peptide into antibody mold, obtained in this study, show that biochemical data and computational approaches provide results comparable to X-ray crystallography.

Amelogenins are a group of extracellular enamel matrix proteins which are believed to be involved in the regulation of the size and habit of enamel crystals. The aim of this study was to compare the solubility properties of several amelogenins in various pH (4.0-9.0) solutions with an ionic strength (IS) of 0.15 M using the Micro BCA protein assay at 25 degrees C or 37 degrees C. The solubility of the recombinant amelogenin rM179 was lowest (0.7 mg/ml) close to its isoelectric point and it increased below and above this point. The solubility of the recombinant amelogenin rM166 remained almost the same (1-2 mg/ml) as the pH rose from 6.0 to 9.0 and it increased as the solution became more acidic. Synthetic "tyrosine-rich amelogenin polypeptide" (TRAP) was extremely insoluble (<0.2 mg/ml) in the pH range studied while synthetic "leucine-rich amelogenin polypeptide" (LRAP) was readily soluble (>3.3 mg/ml). The native porcine amelogenin with apparent molecular weight 25 kDa shared similar solubility behavior to rM179. The porcine 23 kDa amelogenin was only sparingly soluble (0.3-0.8 mg/ml) over a wide range of pH. Interestingly, the porcine 20 kDa amelogenin was remarkably soluble in the pH range of 4.0 to 6.0 (approximately 12 mg/ml), but the solubility dropped strikingly to only approximately 0.2 mg/ml at pH larger than approximately 7.0. The strong dependence of amelogenin solubility on solution pH may be involved in the regulation of aggregation, enzymatic degradation and the binding properties of amelogenins, thus playing an important role in enamel biomineralization.

The native b-D-glucan exohydrolase isoenzyme ExoI from barley seedlings, designated HvExoI, was the first GH3 glycoside hydrolase, for which a crystal structure was determined. A precise understanding of relationships between structure and function in this enzyme has been gained by structural and enzymatic studies. To allow testing of hypotheses gained from these studies, an efficient system for expression of HvExoI in Pichia pastoris was developed using a codon-optimized cDNA. Protein expression at a temperature of 20°C yielded a recombinant enzyme, designated rHvExoI, which had molecular masses of 70-110 kDa due to heavy glycosylation at Asn221, Asn498 and Asn600, the three sites of N-glycosylation in native HvExoI. Most of the N-linked carbohydrate could be removed from rHvExoI, resulting in N-deglycosylated rHvExoI with a substantially decreased molecular mass of 67 kDa. rHvExoI was able to hydrolyse barley (1,3;1,4)-b-D-glucan, laminarin and lichenans. The catalytic efficiency value k cat /K M of rHvExoI with barley (1,3;1,4)-b-D-glucan was similar to that reported for native HvExoI. Further, laminaribiose, cellobiose and gentiobiose were formed through transglycosylation reactions with 4-nitrophenyl b-D-glucoside and barley (1,3;1,4)-b-D-glucan. Overall, the biochemical properties of rHvExoI were similar to those reported for native HvExoI, although differences were seen in thermostabilities and hydrolytic rates of certain blinked glucosides.

We developed a protocol for the fast purification of small proteins and peptides using heat incubation as the first purification step. The proteins are expressed from a new bacterial expression vector (pETM-90) fused to the C-terminus of thermostable Ftr from Methanopyrus kandleri. The vector further contains a 6xHis-tag to allow immobilised metal ion affinity purification and a TEV protease cleavage site to enable the removal of the His-tag and fusion partner. Heat incubation induces the specific denaturation and precipitation of the Escherichia coli proteins but not of the thermostable fusion protein. Using the fusion construct and the heat incubation protocol a number of fusion proteins were purified to near homogeneity. The thermostability was ensured when Ftr had a molecular weight higher than twice the target protein. The obtained purification yields were similar and, in some cases, even higher than the ones obtained by affinity purification with the same Ftr-fusion proteins or the same target proteins fused to other often used partners such as NusA, GST, or DsbA. The protocol does not depend on a specific thermostable protein as was shown by the exchange of Ftr for M. kandleri Mtd. Purification by heat incubation is a fast and inexpensive alternative to chromatographic techniques, particularly suitable for the production of antigenic sequences for which the loss of native structure is not detrimental. We proved that it can be easily automated.

Arabidopsis thaliana BRAHMA (BRM, also called AtBRM) is a SNF2 family protein homolog of Brahma, the ATPase of the Drosophila SWI/SNF complex involved in chromatin remodeling during transcription. Here we show that, in contrast to its Drosophila counterpart, BRM is not an essential gene. Thus, homozygous BRM loss of function mutants are viable but exhibit numerous defects including dwarfism, altered leaf and root development and several reproduction defects. The analysis of the progeny of self-fertilized heterozygous brm plants and reciprocal crosses between heterozygous and wild type plants indicated that disruption of BRM reduced both male and female gametophyte transmission. This was consistent with the presence of aborted ovules in the selffertilized heterozygous flowers that contained arrested embryos predominantly at the two terminal cells stage. Furthermore, brm homozygous mutants were completely sterile. Flowers of brm loss-of-function mutants have several developmental abnormalities, including homeotic transformations in the second and third floral whorls. In accordance with these results, brm mutants present reduced levels of APETALA2, APETALA3, PISTILLATA and NAC-LIKE, ACTIVATED BY AP3/PI. We have previously shown that BRM strongly interacts with AtSWI3C. Now we extend our interaction studies demonstrating that BRM interacts weakly with AtSWI3B but not with AtSWI3A or AtSWI3D. In agreement with these results, the phenotype described in this study for brm plants is very similar to that previously described for the AtSWI3C mutant plants, suggesting that both proteins participate in the same genetic pathway or form a molecular complex.

Recombinant mouse protein C was cloned, expressed, purified, and activated by Protac or thrombin. The anticoagulant activities of mouse and human activated protein C (APC) were compared using mouse and human plasma and the neuroprotective properties of murine APC were studied in an ischemic stroke model. Both human APC and mouse APC prolonged the activated partial thromboplastin time in a dose-dependent manner, but mouse APC was sixfold more effective than human APC as an anticoagulant in mouse plasma. Human protein S enhanced prolongation of the APTT clotting time of human plasma by human APC, but not by mouse APC. Hydrolysis of the S-2366 chromogenic substrate by murine APC was essentially identical to human APC. Mouse plasma contains 75 nM protein C. In a murine ischemic stroke model based on middle cerebral artery occlusion, murine APC was highly neuroprotective. The results show that recombinant murine APC is functionally similar to human APC both in vitro and in vivo and that it displays significant species specificity. The results imply that murine APC is notably superior to human APC for studies of murine disease models, including thrombosis and ischemic brain injury.

Two splice variants of the 5-HT 7 receptor were identified in human brain that differ in the lengths of their intracellular carboxy terminal tail. Identification of the variants of this receptor is of particular interest since the 5-HT 7 receptor is known to have a high affinity for a number of antidepressants and is localized in brain regions thought to be implicated in depression. The two isoforms are expressed in roughly equal amounts in various regions of the human brain. When expressed in NIH-3T3 cells, both variants encode functional 5-HT 7 receptors, positively coupled to adenylyl cyclase. We suggest that both variants are derived from a single gene by alternative mRNA splicing. Furthermore, our results from Southern blot analysis studies suggest that additional 5-HT 7 receptor genes may exist in human.

The aggregation of R-synuclein is believed to play an important role in the pathogenesis of Parkinson's disease as well as other neurodegenerative disorders ("synucleinopathies"). However, the function of R-synuclein under physiologic and pathological conditions is unknown, and the mechanism of R-synuclein aggregation is not well understood. Here we show that R-synuclein forms a tight 2:1 complex with histones and that the fibrillation rate of R-synuclein is dramatically accelerated in the presence of histones in vitro. We also describe the presence of R-synuclein and its co-localization with histones in the nuclei of nigral neurons from mice exposed to a toxic insult (i.e., injections of the herbicide paraquat). These observations indicate that translocation into the nucleus and binding with histones represent potential mechanisms underlying R-synuclein pathophysiology.

1 The abbreviations used are: PI(3)P, phosphatidylinositol 3-phosphate; Ins(1,3)P 2 , inositol(1,3)diphosphate; FRET, fluorescence resonance energy transfer; GFP, green fluorescent protein; EGFP, enhanced GFP; YFP, yellow fluorescent protein; CFP, cyan fluorescent protein; TL, turret loops; DI, dimer interface loops.

In order to identify immunoreactive Bartonella henselae proteins, B. henselae antiserum from an experimentally infected cat was used to screen a B. henselae genomic DNA expression library. One immunoreactive phage clone contained a gene (p26) with significant nucleotide identity with orthologs in brucellae, bartonellae, and several plant-associated bacteria. p26 gene sequences from four B. henselae strains, one B. koehlerae strain, and one B. clarridgeiae strain were cloned. Comparative nucleotide sequence analysis showed that p26 is a potential marker for molecular diagnosis of infection, as well as for identification to species level and genotyping of Bartonella sp. isolates. Alignment of the predicted amino acid sequences illustrated conserved putative protein features including a hydrophobic transmembrane region, a peptide cleavage site, and four dominant antigenic sites. Expression of p26 in Escherichia coli produced two proteins (26 and 27.5 kDa), both of which were reactive with feline anti-B. henselae antisera. Furthermore, murine hyperimmune serum raised against either recombinant protein reacted with both proteins. No reactivity to either recombinant protein was detected in nonimmune serum, and reactivity persisted as long as 20 weeks for one cat. The p26 protein product is an immunodominant antigen that is expressed during infection in cats as a preprotein and is subsequently cleaved to form mature P26.

Xenopus liver contains a protein inhibitor of glucokinase that, in contrast to the mammalian regulatory protein of glucokinase, is insensitive to fructose 6-phosphate and fructose 1-phosphate [Vandercammen A. & Van Schaftingen, E. (1993) Biochem. J. 294, 551-556]. The purpose of this work was to compare the primary structure and other properties of this Xenopus protein with those of its rat liver counterpart. A Xenopus laevis liver cDNA library was screened using the cDNA encoding the rat liver regulatory protein as a probe. The cloned cDNA was 2534 bp long and encoded a 619-amino-acid protein with a molecular mass of 68695 Da and 57% identity with the rat liver regulatory protein. This identity was only about 30% in an internal region (amino acids 349-381) and in the 70 carboxy terminal-residues. The Xenopus cDNA was expressed in Escherichia coli and the recombinant regulatory protein was purified to near homogeneity and found to have the same size, reactivity to antibodies and eff...

Transgenesis has been used for expressing human lysozyme (hLZ) in the milk of livestock to improve their disease resistance. Here we describe a human lactoferrin (hLF) BAC as a candidate vector for high-level expression of hLZ in the milk of transgenic mice. Using recombineering, hLF genomic DNA in the hLF BAC was replaced by the hLZ gene (from the ATG start codon to the TAA stop codon), and flanking regions of the hLF gene (a 90-kb 5 0 and a 30-kb 3 0) were used as transcriptional control elements for hLZ expression. When this construct was used to generate transgenic mice, rhLZ was highly expressed in the milk of four transgenic mouse lines (1.20-1.76 g/L), was expressed at a lower level in one additional line (0.21 g/L). rhLZ from the milk of these transgenic mice exhibited the same antibacterial activity as native hLZ. Our results suggest a potential approach for producing large amounts of hLZ in the milk of livestock. Keywords Recombinant human lysozyme (rhLZ) Á Recombineering Á Human lactoferrin bacterial artificial chromosome (hLF BAC) Á Transgenic mice Á Milk Electronic supplementary material The online version of this article (

Recombinant human activated protein C (drotrecogin alfa [activated]--DAA) demonstrated in Phase III controlled clinical studies significant reduction of mortality in patients with severe sepsis and high risk of death. The aim of the study was to assess the therapeutic efficacy of DAA in patients included in the National Severe Sepsis Register in Poland. The analysis included 3233 cases of severe sepsis reported between 04.2003 and 11.2005. 302 patients (9.3%) were treated with DAA. The clinical course of the disease in DAA and non-DAA treatment groups was compared. Logistic regression models for the effects of independent variables on the risk of death (dependent variable) were developed. In the patients treated with DAA, the relative risk of death was lower by 31% than in those who were not treated. In a multivariate logistic regression model, the use of DAA was, independently of the patient's age, severity of the clinical condition and type of organ dysfunction, the most signi...

The Ig-genes of the heavy chains in anti-D-specific hybridomas and Fab/scFv-fragments selected from phage-display libraries are restricted to a group of closely related genes (IGHV3s genes). We analyzed the Ig-gene repertoire in anti-D-specific B cells of two hyperimmunized donors using a completely different method. Single B cells were cultured for 10 days in an EL4.B5 culture system. mRNA from anti-D-producing B cells was reverse transcribed into cDNA. Heavy-and light-chain gene rearrangements were amplified by PCR reactions, sequenced and cloned into a pNUT-vector system, thereby allowing the production of complete IgG and IgM. Eleven anti-D-specific B-cell clones were isolated and analyzed. Eight of these clones (including IgM-producing clones) had IGHV3s genes. We demonstrated that functional anti-D-specific IgM (4 clones) and IgG (2 clones) was produced. Using a new method, we analyzed the IGHV gene repertoire of anti-D-specific B cells of hyperimmunized donors and showed that it is indeed restricted. Moreover, we found a high frequency (1:100 and 1:500) of anti-D-specific B cells in the peripheral B cells of hyperimmunized donors. We suggest that this approach could be applied for the selection of human mAbs from immunized donors and for the analysis of Ig-gene repertoires at the single-B cell level.

The current method for generating lymphokine-activated killer (I VK) cells for use in human clinical trials is both labor intensive and expensive. Therefore, we altered cell culture conditions to determine whether LAK cells with enhanced lytic activity could be generated. Culture of normal human peripheral blood leukocytes for 7 days generated LAK cells with 4-fold more lytic activity than culture for 3 days. Although cell viability over this 7-day period dropped from 94% on Day 3 to 73% by Day 7, the recovery of cells from culture increased from 61 to 106%. If cells were exposed to CO., lytic activity was further enhanced by up to 30-fold. Culture at a density of 1 or 2.5 x III"cells/ml caused no difference in cell viability, recovery, or LAK activity when cells were cultured for up to 4 days; however, when cells were cultured for longer times, an initial density of 1 x IO'1cells/ml yielded maximal LAK activity. Several commercially available serum-free defined media as well as human serum albumin supported LAK cell activation comparable to serum-containing media over a 4-day culture period. One defined medium, AIM V, supported LAK cell activation over a 7-day period even when cells were cultured at a density twice as high (2 x III'' cells/ml) as cells cultured in serumcontaining medium. The results demonstrate that simple manipulation of human LAK cell culture conditions generates cells with greatly enhanced lytic activity and that serum-containing medium may not be necessary for generating LAK cells under the current clinical protocols.

Mutagenesis studies have been used to investigate the role of a heme ligand containing protein loop (67-79) in the activation of diheme peroxidases. Two mutant forms of the cytochrome c peroxidase of Pseudomonas aeruginosa have been produced. One mutant (loop mutant) is devoid of the protein loop and the other (H71G) contains a non-ligating Gly at the normal histidine ligand site. Spectroscopic data show that in both mutants the distal histidine ligand of the peroxidatic heme in the un-activated enzyme is lost or is exchangeable. The un-activated H71G and loop mutants show, respectively, 75% and 10% of turnover activity of the wild-type enzyme in the activated form, in the presence of hydrogen peroxide and the physiological electron donor cytochrome c 551. Both mutant proteins show the presence of constitutive reactivity with peroxide in the normally inactive, fully oxidised, form of the enzyme and produce a radical intermediate. The radical product of the constitutive peroxide reaction appears to be located at different sites in the two mutant proteins. These results show that the loss of the histidine ligand from the peroxidatic heme is, in itself, sufficient to produce peroxidatic activity by providing a peroxide binding site and that the formation of radical intermediates is very sensitive to changes in protein structure. Overall, these data are consistent with a major role for the protein loop 67-79 in the activation of di-heme peroxidases and suggest a ''charge hopping'' mechanism may be operative in the process of intra-molecular electron transfer.

Perinatal care in Japan has progressed rapidly in recent decades, remarkably reducing maternal, perinatal and neonatal mortality rates. This is attributable not only to the sustained efforts and dedication of past obstetricians and midwives, but also to the collective results achieved by the Japan Society of Obstetrics and Gynecology and healthcare administration, including research on advanced medical care, education, medical care improvements and establishing perinatal care centers. Although the maternal mortality rate was in steady decline until 2007 (3.1/100 000 births), it repeatedly fluctuated thereafter, plateauing at 3.4 per 100 000 births in 2013 and 2.7 per 100 000 births in 2014. Thus, the Perinatology Committee has analyzed the current situation of maternal deaths and has proposed countermeasures to reduce such death. The items deliberated upon by related subcommittees in 2015 are presented herein. The addition of indications for 'fibrinogen concentrate', 'ep...

Anticoagulation therapy for cardiopulmonary bypass in patients with recently diagnosed heparin-induced thrombocytopenia can be particularly challenging. Although heparin is the standard of care, in these situations anticoagulation is achieved with alternative agents such as direct thrombin inhibitors. Therapeutic concentrations are difficult to assess with direct thrombin inhibitors, and their use is riddled with bleeding and thrombotic complications. We report the successful use of a specific chromogenic antifactor IIa assay in a patient with heparin-induced thrombocytopenia who received anticoagulation therapy with bivalirudin during cardiopulmonary bypass for coronary artery bypass graft surgery.

Cheese whey (CW) is the major subproduct from cheese manufacturing and it is considered as a waste pollutant since its high content of lactose. In this work a fermentation process for the production of penicillin acylase (PA) by a recombinant Escherichia coli and using CW as unique carbon source and inducer was developed. A design factorial 3 2 was used to evaluate the influence of independent variables (dissolved oxygen and CW concentration) on the ability of E. coli W3110/pPA102 to produce PA. Maximum specific PA activity of 781 U g À1 was attained at 5 g L À1 of CW and 3% dissolved oxygen. The results showed that CW can be used successfully as unique carbon source and inducer for the production of recombinant proteins using constructions driven by the lac promoter and this way reducing the discharges of that pollutant to the environment. # .mx (A. De León-Rodríguez).

Protein splicing elements, termed inteins, provide a fertile source for innovative biotechnology tools. First harnessed for protein purification, inteins are now used to express cytotoxic proteins, to segmentally modify or label proteins, to cyclize proteins or peptides, to study structure-activity relationships and to generate reactive polypeptide termini in expressed proteins for an expanding list of chemoselective reactions, including protein ligation.

AbstractöThere is growing evidence to suggest that growth hormone plays a role in the growth and development of the CNS. Speci¢cally, growth hormone has been implicated in promoting brain growth, myelination, neuronal arborisation, glial di¡erentiation and cognitive function. Here we investigate if growth hormone has a role in the recovery from an unilateral hypoxic^ischaemic brain injury. Using moderate (15 min hypoxia) and severe (60 min hypoxia) models of hypoxic^ischaemia in juvenile rats and standard immunohistochemical techniques, we found intense growth hormone-like immunoreactivity present within regions of cell loss by 3 days (P 6 0.05). Growth hormone-like immunoreactivity was observed on injured neurones, myelinated axons, glial cells within and surrounding infarcted tissue and on the choroid plexus plus ependymal cells within the injured hemisphere. The pattern of immunoreactivity suggests that (a) growth hormone (or a growth hormone-like substance) is transported via the cerebrospinal £uid and (b) that growth hormone (or a growth hormone-like substance) is acting in a neurotrophic manner speci¢cally targeted to injured neurones and glia.

Food allergies are increasing worldwide, demonstrating a considerable public health concern. Shellfish allergy is one of the major food groups causing allergic sensitization among adults and children, affecting up to 2% of the general world population. Tropomyosin (TM) is the major allergen in shellfish and frequently used in the diagnosis of allergic sensitization and the detection of cross-contaminated food. To improve and establish better and more sensitive diagnostics for allergies and immunotherapeutics, large quantities of pure allergens are required. To establish a reproducible method for the generation of pure recombinant tropomyosin we utilized in this study different Escherichia coli strains (NM522, TOP10 and BL21(DE3)RIPL). In addition, isopropylβ-D-thiogalactoside (IPTG) induction was compared with a novel auto-induction system to allow the generation of larger quantities of recombinant allergen. We demonstrated that the B-strain of E. coli is better for the expression of TM compared to the K-strain. Moreover, a higher yield could be achieved when using the auto-induction system, with up to 62 mg/l. High yield expressed recombinant TM from King prawn (KP) was compared to recombinant TM from Black tiger prawn (Pen m 1). We demonstrated that recombinant TM from KP and known isoallergen Pen m 1 have very similar molecular and immunological characteristics. Overall, we demonstrate that autoinduction can be used to express larger quantities of recombinant allergens for the development of diagnostic, to quantify allergens as well as immunotherapeutics employing isoallergens.

Background About one in every four cases of occupational rhinitis recorded in Finland is animal-induced. Bovine allergens are the most important in this respect and the largest patient group consists of dairy farmers. Allergen immunotherapy, if proven effective, safe and feasible, would be ideal for their treatment. The development of recombinant allergens has offered new potential therapeutic prospects. Fragments of recombinant Bos domesticus (Bos d 2) allergen could be suitable for this purpose because they are recognized by T cells but their IgE-binding capacity is attenuated.

Molecular chaperones have been used for the improved expression of target proteins within heterologous systems; however, the chaperone and target protein have seldom been matched in terms of origin. We have developed a heterologous co-expression system that allows independent expression of the plasmodial chaperone, PfHsp70, and a plasmodial target protein. In this study, the target was Plasmodium falciparum GTP cyclohydrolase I (PfGCHI), the first enzyme in the plasmodial folate pathway. The sequential expression of the molecular chaperone followed by the target protein increased the expression of soluble functional PfGCHI. His-tagged PfGCHI was successfully purified using nickel affinity chromatography, and the specific activity was determined by high performance liquid chromatography with spectrofluorometeric detection to be 5.93 nmol/hr/mg. This is the first report of a heterologous co-expression system in which a plasmodial chaperone is harnessed for the improved production and purification of a plasmodial target protein.

A series of 10 1,4-bis(3-aminopropyl)piperazine compounds was found to display antiplasmodial activity with 50% growth inhibition between 30 and 250 nM, on three Plasmodium falciparum strains differently sensitive to chloroquine. By affinity chromatography using one of these compounds, a 52-kDa protein was isolated from P. falciparum, microsequenced and cloned. It corresponded to a single copy gene encoding a 453 amino acid protein displaying the typical features of protein disulfide isomerases, a thiol metabolizing enzyme belonging to the thiol : disulfide oxidoreductase superfamily, which was not previously described in malarial species. ß

Objective: To evaluate the effect of treatment with peginterferon alpha-2b and ribavirin on liver histology in patients with chronic hepatitis C (CHC) with or without HIV infection. Methods: Patients received peginterferon alpha-2b (1.5 m/kg/week during the first 4 weeks; 1.0 m/kg/week thereafter) plus ribavirin (800e1200 mg/day, adjusted for weight) for 24 (genotypes 2/3) or 48 weeks (genotypes 1/4). Paired liver biopsy specimens were obtained at baseline and at the end of follow-up. Results: 108 paired biopsy specimens were available: 67 from HCV-monoinfected and 41 from co-infected patients. At the end of follow-up, necroinflammatory activity (NIA) was significantly reduced (P < 0.001), and fibrosis scores improved by !1 point (Ishak et al criteria) in 65.7% of HCV-monoinfected patients. In co-infected patients, NIA was significantly reduced (P < 0.001), and fibrosis scores improved by !1 point in 42.5% of cases. In both groups, results were better for patients who attained sustained virological response (SVR). HCV RNA was undetectable in the second biopsy specimens of all patients who attained SVR. Conclusion: Liver fibrosis is reduced significantly after a course of therapy in patients with chronic hepatitis C. Reduction of fibrosis is more significant in patients who are monoinfected with HCV and in those who attained SVR.

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Background In patients with ST-segment elevation myocardial infarction (STEMI) triaged to primary percutaneous coronary intervention (PCI), anticoagulation often is initiated in the ambulance during transfer to a PCI site. In this prehospital setting, bivalirudin has not been compared with standard-of-care anticoagulation. In addition, it has not been tested in conjunction with the newer P2Y 12 inhibitors prasugrel or ticagrelor.

Protein A chromatography is widely employed for the capture and purification of antibodies and Fc-fusion proteins. Due to the high cost of protein A resins, there is a significant economic driving force for using these chromatographic materials for a large number of cycles. The maintenance of column performance over the resin lifetime is also a significant concern in large-scale manufacturing. In this work, several statistical methods are employed to develop a novel principal component analysis (PCA)-based tool for predicting protein A chromatographic column performance over time. A method is developed to carry out detection of column integrity failures before their occurrence without the need for a separate integrity test. In addition, analysis of various transitions in the chromatograms was also employed to develop PCA-based models to predict both subtle and general trends in real-time protein A column yield decay. The developed approach has significant potential for facilitating timely and improved decisions in large-scale chromatographic operations in line with the process analytical technology (PAT) guidance from the Food and Drug Administration (FDA).

Proteins derived from the E6, E7 and Ll ORFs of HPV16 and the E7 ORF of HPVI 8 were produced in insect cells using a baculovirus expression system. HPV ORFs were inserted into baculovirus transfer vectors pAcYM1 or pVL1393/2, and recombinant baculoviruses isolated using a combination of limiting dilution and plaque assay. Using HPV-specific antisera and monoclonal antibodies HPV proteins were identified in lysates of Spodoptera fvugiperdu 11 ce s infected with HPV-recombinant baculovirus. Immunoreactive HPV16 E7 protein produced in Sf-21 cells had an apparent M, of 19 kDa, larger than that predicted from the amino acid sequence, and similar to that of native HPV16 E7 protein in HeLa and CaSki cells. The apparent M, of recombinant HPV 1%E7, HPV 16-Ll and HPVl6-E6 proteins was equivalent to the M, values predicted from the amino acid sequence. Thermostability studies revealed that the half-life of HPVl6-E7 protein in Sf-21 cell lysate was approx. 20 h at 4°C 2 h at 22°C and less than 30 min at 37°C. HPV16 Ll, HPV16 E7 and HPVIS E7 proteins were predominantly localised in the nucleus of recombinant baculovirus-infected Sf-2 1 cells, whereas recombinant HPV 16 E6 protein was localised in both the cytoplasm and nucleus of infected insect cells. Northern blot analysis of RNA derived from insect cells infected with vAc 16E6E7, a recombinant baculovirus containing both HPV16 E6 and E7 ORF's, revealed the presence of only E6 ORF transcripts, suggesting that the v Corresponding author. **Present address: NIAID, Bethesda, MD. USA 304 splicing of RNA products derived from the E6 and E7 ORF's, as observed in cervical cancer-derived cell lines, is not performed in insect cells. Baculovirusderived HPV proteins have similar biological properties to the native proteins and should be suitable for studies on the immunology of HPV.

Sundaresan, A., D. Risin, and N. R. Pellis. Modeled microgravity-induced protein kinase C isoform expression in human lymphocytes. space travel, the crew is exposed to microgravity and radiation that invoke potential hazards to the immune system. T cell activation is a critical step in the immune response. Receptor-mediated signaling is inhibited in both microgravity and modeled microgravity (MMG) as reflected by diminished DNA synthesis in peripheral blood lymphocytes and their locomotion through gelled type I collagen. Direct activation of protein kinase C (PKC) bypassing cell surface events using the phorbol ester PMA rescues MMG-inhibited lymphocyte activation and locomotion, whereas the calcium ionophore ionomycin had no rescue effect. Thus calcium-independent PKC isoforms may be affected in MMG-induced locomotion inhibition and rescue. Both calcium-dependent isoforms and calcium-independent PKC isoforms were investigated to assess their expression in lymphocytes in 1 g and MMG culture. Human lymphocytes were cultured and harvested at 24, 48, 72, and 96 h, and serial samples were assessed for locomotion by using type I collagen and expression of PKC isoforms. Expression of PKC-␣, -␦, and -⑀ was assessed by RT-PCR, flow cytometry, and immunoblotting. Results indicated that PKC isoforms ␦ and ⑀ were downregulated by Ͼ50% at the transcriptional and translational levels in MMG-cultured lymphocytes compared with 1-g controls. Events upstream of PKC, such as phosphorylation of phospholipase C␥ in MMG, revealed accumulation of inactive enzyme. Depressed calcium-independent PKC isoforms may be a consequence of an upstream lesion in the signal transduction pathway. The differential response among calcium-dependent and calcium-independent isoforms may actually result from MMG intrusion events earlier than PKC, but after ligand-receptor interaction.