Sadegh Hasannia
Tarbiat Modares University, Biochemistry, Faculty Member
Background: Regarding retained cement acts as an idiopathic cause for early implant loss, cement selection with the least toxicity in the peri-implant hard and soft tissues is important. The present study aimed to evaluate the... more
Background: Regarding retained cement acts as an idiopathic cause for early implant loss, cement selection with the least toxicity in the peri-implant hard and soft tissues is important. The present study aimed to evaluate the cytotoxicity of three different types of temporary cements and titanium cemented with each cement after direct exposure to human gingival fibroblasts (HGF) and MG-63 osteoblast-like cells.Methods: In this in vitro study, zinc oxide-eugenol (ZOE), eugenol-free zinc oxide (ZONE), and resin (R) cements prepared in cylindrical forms with a similar dimension were used. Each cement was placed on titanium disks to prepare cemented titanium samples. MTT assay was applied at 24- and 72-hour, and 7-day intervals to evaluate cytotoxicity.Results: All the cements decreased cell viability in both cell lines significantly. None of the cements exhibited cellular viability percentages higher than the minimum percentage (70%) required for biocompatibility. The cemented titaniu...
Research Interests:
Abstract Context Bacillus anthracis secretes a tripartite toxin comprising protective antigen (PA), edema factor (EF), and lethal factor (LF). The human anthrax vaccine is mainly composed of the anthrax protective antigen (PA).... more
Abstract Context Bacillus anthracis secretes a tripartite toxin comprising protective antigen (PA), edema factor (EF), and lethal factor (LF). The human anthrax vaccine is mainly composed of the anthrax protective antigen (PA). Considerable efforts are being directed towards improving the efficacy of vaccines because the use of commercial anthrax vaccines (human/veterinary) is associated with several limitations. Objective In this study, a triple chimeric antigen referred to as ELP (gene accession no: MT590758) comprising highly immunogenic domains of PA, LF, and EF was designed, constructed, and assessed for the immunization capacity against anthrax in a guinea pig model. Materials and methods Immunization was carried out considering antigen titration and immunization protocol. The immunoprotective efficacy of the ELP was evaluated in guinea pigs and compared with the potency of veterinary anthrax vaccine using a challenge test with B. anthracis 17JB strain spores. Results The results demonstrated that the ELP antigen induced strong humoral responses. The T-cell response of the ELP was found to be similar to PA, and showed that the ELP could protect 100%, 100%, 100%, 80% and 60% of the animals from 50, 70, 90, 100 and 120 times the minimum lethal dose (MLD, equal 5 × 105 spore/ml), respectively, which killed control animals within 48 h. Discussion and conclusions It is concluded that the ELP antigen has the necessary requirement for proper immunization against anthrax and it can be used to develop an effective recombinant vaccine candidate against anthrax.
Research Interests:
Research Interests:
0! ! + P )< Q R M = ) #% < $A O #N: ; ' A" S3 #T S: 1 O 9U 1 9 # 9 )93 ) #% )-$A 1 J -$A 3 1 %( #V > / 1 " C ) #% 93 9= 1 9 H" 1; #95" W2 9=# X9 "I Y Z 3 3 ) ! 5 O 3 & [ \ ] ^ \ ] / = ; = 3 " ,... more
0! ! + P )< Q R M = ) #% < $A O #N: ; ' A" S3 #T S: 1 O 9U 1 9 # 9 )93 ) #% )-$A 1 J -$A 3 1 %( #V > / 1 " C ) #% 93 9= 1 9 H" 1; #95" W2 9=# X9 "I Y Z 3 3 ) ! 5 O 3 & [ \ ] ^ \ ] / = ; = 3 " , : 7 #25 3 1 . / / 7 #25 < C " 1 + / 0& ; R .D ; # ) #% ^_ 7 #25 ) #% . 7 #25 ) #% ] 7 #25 ) #% . R )9 #% 7 #25 . ` 7 #25 ) #% " a 7 #25 ; b 7 #25 ) #% = 3 # 1 / #3 C 2" 3425 / " 5 !9 " )9< Q #9 1 9 )9< ( /9 )$9= c > #9d /93 O 9 P Y `]aa \ _ Z . Y aa` \ _ Z . Y _ \ _ Z . Y _ ^` \ _ Z . Y __[] \ _ Z = " 0 Y _^^_ \ _ CZ 6 ! 3 2 7 3 + P W2 #25 .O .W2 =# X "I .
Research Interests:
Abstract Collagen as a biomaterial is commonly obtained from terrestrial animals. However, nowadays, the use of collagen with terrestrial animals' sources due to possible transmission of infectious diseases and religious beliefs is... more
Abstract Collagen as a biomaterial is commonly obtained from terrestrial animals. However, nowadays, the use of collagen with terrestrial animals' sources due to possible transmission of infectious diseases and religious beliefs is restricted. This study was conducted to evaluate the physicochemical characterization, morphology, and biocompatibility of extracted collagen from silver carp fish skin by-product. Type I collagen was extracted from the silver carp fish skin by-product using acetic acid and pepsin enzyme. The results showed that the extraction yield of ASC and PSC was 42.85% and 58.75% (on a dry weight basis), respectively. The presence of two different α-chains confirmed the type I collagen structure for both collagens. Moreover, FTIR spectra investigation demonstrated the triple helical in ASC and PSC collagens. The PSC showed higher imino acids content than ASC. Hence, the fractional viscosity and DSC curves revealed higher Td (30 °C), Ts (81 °C), and Tm (209 °C) for PSC than ASC (28.73 °C, 77 °C, and 187 °C, respectively). Finally, observations of the microscopic and the cell viability evaluation confirmed biocompatibility and suitable structure to cell growth. Accordingly, the obtained collagen from silver carp fish skin can be a proper alternative for terrestrial animals’ collagen and a safe biomaterial for biomedical use.
Research Interests:
Abstract In the present study, Poly l -lactic acid (PLLA) resin compatible with digital light processing (DLP) 3D printing method was synthesized to produce hard tissue scaffolds. PLLA has been chosen as a decent material to mimic... more
Abstract In the present study, Poly l -lactic acid (PLLA) resin compatible with digital light processing (DLP) 3D printing method was synthesized to produce hard tissue scaffolds. PLLA has been chosen as a decent material to mimic biological structures due to its relatively high strength as well as proper biocompatibility and biodegradation rate. After synthesis and functionalization of PLLA, using a facile method, porous models with 600-micron pore size and 70 % nominal porosity were designed and fabricated via DLP technique in order to investigate the effects of the two process parameters, light exposure time and dye concentration, on compressive strength and morphological features of the printed samples. The experimental results were then reconciled with plotted working curves for each dye concentration to validate the defined exposure time levels. It was concluded that the synthesized polymer and the used method of 3D printing are suitable for fabricating scaffolds with intricate structures. Moreover, by conducting the compression test, a maximum 2.2 MPa strength was achieved for the sample with minimum dye concentration and maximum exposure time. From the biological point of view, no cytotoxic effect was seen after a 3-day in vitro cell viability testing. Altogether, it was shown that optimal adjustment of the process parameters is essential to achieve appropriate dimensional and mechanical properties, which were acknowledged by plotted working curves.
Research Interests:
Introduction : The PCR is an indispensable method in biotechnology. One of the limitations of PCR is the size of the amplified DNA product. The basis for this constraint is the error rate and low proccessivity and elongation rate of... more
Introduction : The PCR is an indispensable method in biotechnology. One of the limitations of PCR is the size of the amplified DNA product. The basis for this constraint is the error rate and low proccessivity and elongation rate of different thermostable DNA polymerases. However, if an efficient thermostable PCR enzyme with higher accuracy, elongation velocity and proccessivity such as KOD DNA polymerase is used an increased yield of a high fidelity long_range PCR products can be produced. The aim of this study was to optimize of the production and purification of a functional KOD DNA polymerase. Method : We have purchased a pET17b plasmid that had KOD DNA polymerase gene in multiple cloning site and transform it in the expressing strain BL21(DE3) containing the pLysE or pLysS plasmid. Production of the 90-kDa protein was induced by different concentrations of IPTG. Purification were performed by heating, ammonium sulfate precipitation and chromatography with DEAE-sepharose. Purified protein was identified by SDS-PAGE and AgNO3 staining. The activity of the obtained enzyme was measured by comparing the intensities of the produced DNA bands in PCR reactions. Results: The correct framing of the gene and its orientation were analyzed by digestion and colony PCR. The plasmid was stable in BL21(DE3) containing the pLysS plasmid. Addition of glycerol, Triton X-100, Tween 20, dextrose and protease inhibitor cocktail increased enzyme stability. Conclusions: We have found that pET17b expression vector is toxic or unstable in the expressing strain BL21(DE3), even in the absence of induction. However BL21(DE3) containing the pLysS plasmid suppresses expression prior to induction and was able to produce greater amount of enzyme after induction by IPTG.
Research Interests:
Research Interests:
Zein nanoparticles as a carrier system for BMP6-derived peptide were prepared by liquid-liquid phase separation procedure and characterized with SEM, DLS, FTIR and thermogravimetric methods. After peptide encapsulation, nanoparticle size... more
Zein nanoparticles as a carrier system for BMP6-derived peptide were prepared by liquid-liquid phase separation procedure and characterized with SEM, DLS, FTIR and thermogravimetric methods. After peptide encapsulation, nanoparticle size increased from 236.3 ± 92.2 nm to 379.4 ± 116.8 nm. The encapsulation efficiency of peptide was 72.6% and the release of peptide from Zein nanoparticles was partly sustained in trypsin containing phosphate buffered saline (pH 7.4) for up to 14 days. Peptide-loaded nanoparticles showed similar cell viability compared with blank ones. ALP activity of C2C12 cells treated with peptide-loaded nanoparticles (500 µg/mL) was evaluated 7, 14, 21 and 28 days after culture. In peptide-loaded nanoparticles, ALP activity was significantly higher (p < .05) compared with other groups at day 14. Alizarin Red S staining showed, C2C12 cells behind peptide-loaded nanoparticles had significantly (p < .05) higher calcium deposition at day 21. The results of RT-qPC...
Research Interests:
Research Interests:
The design of a new truncated and engineered alpha1-antitrypsin based on theoretical studies: an antiprotease therapeutics for pulmonary diseases
Research Interests:
Cholesteryl ester transfer protein (CETP) catalysis the exchange of triglycerides (TG) and cholesterol esters among plasma lipoproteins. It has been shown that variations at CETP locus is important in the levels and activity of CETP and... more
Cholesteryl ester transfer protein (CETP) catalysis the exchange of triglycerides (TG) and cholesterol esters among plasma lipoproteins. It has been shown that variations at CETP locus is important in the levels and activity of CETP and high density lipoprotein (HDL) plasma concentration. In this research, we assessed the relationship between TaqIB CETP polymorphism and high density lipoprotein-cholestrol (HDL-C) concentration in a study sample of 128 Iranian residents. 1Based on our investigations, it was shown that presence of B1B1 genotype related to TaqIB polymorphism was negatively correlated with HDL-C and HDL2-C, but positively correlated with LDL-C. On the other hand, no correlation with HDL3-C was observed. Analysis of HDL-C subfraction in CHD and control subjects revealed that variation of the CETP TaqI B locus was significantly associated with concentration of HDL2-C subclass. Homozygous and heterozygous carried the B2 alleles, compared with B1 homozygote had significantl...
Research Interests:
Research Interests:
Human epidermal growth factor receptor 2 (HER2)-positive breast cancer represents approximately 15-30% of all invasive breast cancers. Despite the recent advances in therapeutic practices of HER2 subtype, drug resistance and tumor... more
Human epidermal growth factor receptor 2 (HER2)-positive breast cancer represents approximately 15-30% of all invasive breast cancers. Despite the recent advances in therapeutic practices of HER2 subtype, drug resistance and tumor recurrence still have remained as major problems. Drug discovery is a long and difficult process, so the aim of this study is to find potential new application for existing therapeutic agents. Gene expression data for breast invasive carcinoma were retrieved from The Cancer Genome Atlas (TCGA) database. The normal and tumor samples were analyzed using Linear Models for Microarray Data (LIMMA) R package in order to find the differentially expressed genes (DEGs). These genes were used as entry for the library of integrated network-based cellular signatures (LINCS) L1000CDS2 software and suggested 24 repurposed drugs. According to the obtained results, some of these drugs including vorinostat, mocetinostat, alvocidib, CGP-60474, BMS-387032, AT-7519, and curcumin have significant functional similarity and structural correlation with FDA-approved breast cancer drugs. Based on the drug-target network, which consisted of the repurposed drugs and their target genes, the aforementioned drugs had the highest degrees. Moreover, the experimental approach verified curcumin as an effective therapeutic agent for HER2 positive breast cancer. Hence, our work suggested that some repurposed drugs based on gene expression data can be noticed as potential drugs for the treatment of HER2-positive breast cancer.
Research Interests:
Research Interests:
Research Interests:
Due to the unique features of xenografts including large supply from donors, minimal risk of human disease transmission, and the lower cost of preparation and production compared to autografts and allografts, they are considered as... more
Due to the unique features of xenografts including large supply from donors, minimal risk of human disease transmission, and the lower cost of preparation and production compared to autografts and allografts, they are considered as attractive alternatives to traditional bone grafts. The animal source accessibility and production process have a direct correlation with the cost and quality of the final product. To evaluate whether the animal source of the bone has any effect on the physicochemical and histological properties of the final xenograft, three deproteinized bone grafts were prepared from sources that are easily available in Iran, including the bovine (DBB), camel (DCB), and ostrich (DOB).
Research Interests:
PURPOSE The present study sought to design a multi-functional fusion peptide with hydroxyapatite (HA) binding domain (HABD) and heparin binding domain (HBD). METHODS The 74 amino acid fusion peptide contained N-terminus of the fibrinogen... more
PURPOSE The present study sought to design a multi-functional fusion peptide with hydroxyapatite (HA) binding domain (HABD) and heparin binding domain (HBD). METHODS The 74 amino acid fusion peptide contained N-terminus of the fibrinogen β chain (β 15-66), double G4S-linker and 12 residues with HA affinity. This construct was designed, synthesized and cloned into pET21a(+) vector and expressed in E.coli. RESULTS HABD facilitated purification of the fusion peptide by HA affinity chromatography. Kinetic peptide binding and release on HA scaffold showed sustained release of peptide for up to 16 days. Competitive ELISA and intrinsic fluorescence assays were applied to determine HBD affinity to bone morphogenetic protein (BMP)-2. The disassociation rate constant (Kd ) for HBD and rhBMP-2 was approximately 9.2 to 12 nM. CONCLUSION The fusion peptide developed in the present study, allowed for streamlined purification on HA affinity chromatography, as well as sustained release from HA scaffold, attributed to its HABD. HBD mediated binding to BMP-2, which may be potentially useful for bone repair. Additional studies, including in vivo investigation will be required to assess the efficacy of the fusion peptide in bone tissue engineering. This article is protected by copyright. All rights reserved.
Research Interests:
INTRODUCTION This study aims to develop and characterize the regenerative potential of an atelopeptidized treated dentin matrix xenograft using in vitro and in vivo models. METHODS Freshly extracted bovine dentin was pulverized into 250-... more
INTRODUCTION This study aims to develop and characterize the regenerative potential of an atelopeptidized treated dentin matrix xenograft using in vitro and in vivo models. METHODS Freshly extracted bovine dentin was pulverized into 250- to 500-μm particles and demineralized with 17% EDTA for 1, 7, and 13 days. The samples were atelopeptidized with pepsin. The degree of demineralization and the effect of atelopeptidization were assessed using field emission scanning electron microscopy combined with energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy, respectively. The expression of dentin matrix acidic phosphoprotein 1, dentin sialophosphoprotein, and osteopontin was evaluated in dental pulp stem cells using quantitative real-time polymerase chain reaction. The samples were then implanted intramuscularly in rats for 30 days, and the inflammatory cells were quantified histologically. RESULTS Field emission scanning electron microscopy combined with energy-dispersive X-ray spectroscopy revealed an exposed tubular structure of dentin after 1 and 7 days of demineralization. Fourier transform infrared spectroscopy confirmed the absence of amide peaks at 1260 to 1640/cm after atelopeptidization. The dental pulp stem cell expression of dentin matrix acidic phosphoprotein 1 and dentin sialophosphoprotein increased in all compared with the untreated control group (P < .05). The maximum expression rates were observed for the 1-day demineralized and atelopeptidized group. The 1-day demineralized group elicited the highest inflammatory response compared with the 7- or 13-day demineralized groups (P < .001). Atelopeptidization significantly decreased the inflammatory response only in the 1-day demineralized dentin group (P < .05). CONCLUSIONS Atelopeptidization of 1-day demineralized dentin xenograft preserved the collagen structure, minimized the immune reaction, and provided sufficient regenerative potential.
Research Interests: Dentistry and Endodontics
One of the main challenges in oral disease is prevention of bacterial infections considering antibiotic resistance as a result of frequent use of conventional antibiotics. A natural alternative to these chemical antibiotics is... more
One of the main challenges in oral disease is prevention of bacterial infections considering antibiotic resistance as a result of frequent use of conventional antibiotics. A natural alternative to these chemical antibiotics is antimicrobial peptide (AMP). LL37, a helical and amphipathic peptide with 37 amino acid residues, is the only cathelicidin-derived form of AMPs in humans that has a broad spectrum of antimicrobial activity (Majewski et al. in Cent Eur J immunol 43(4):453–457, https://doi.org/10.5114/ceji.2018.81355 , 2018). In this study a bi-functional fusion peptide was designed, which consisted of LL-37 peptide linked to a hydroxyapatite (HA) binding peptide through a GGGGS linker. The fusion peptide antimicrobial activity was assessed against both gram-positive and gram-negative bacteria by the microtiter plate method and minimum inhibitory concentrations of 250 µg/ml and 125 µg/ml were obtained for Streptococcus mutans and Escherichia coli , respectively. The binding affinity of the HABP-LL37 fusion peptide to HA-surfaces was confirmed by the peptide release test using the spectrometer method. The HABP-LL37 fusion peptide immobilization on HA surfaces was done using a simple soaking technique. It was shown that 100 mg of the HA polymer disk could load up to 278 μg (55.6%) of LL37-HABP. Evaluation of the cytotoxic properties of the designed fusion peptide before and after immobilization on HA polymer disks against C2C12 cells showed that immobilization resulted in the reduction of HABP-LL37 cytotoxicity. The use of this bi-functional peptide with HA-based biomaterial can result in the development of novel and safe antimicrobial bone substitutes to manage and reduce the complications of device infection.
Research Interests:
Abstract Background Platelet‐rich fibrin (PRF) membranes can preserve alveolar ridge dimension after tooth extraction. Thus, it can be presumed that PRF suppresses the catabolic events that are caused by osteoclastic bone resorption.... more
Abstract Background Platelet‐rich fibrin (PRF) membranes can preserve alveolar ridge dimension after tooth extraction. Thus, it can be presumed that PRF suppresses the catabolic events that are caused by osteoclastic bone resorption. Methods To address this possibility, we investigated the impact of soluble extracts of PRF membranes on in vitro osteoclastogenesis in murine bone marrow cultures. Osteoclastogenesis was induced by exposing murine bone marrow cultures to receptor activator of nuclear factor kappa B ligand (RANKL), macrophage colony‐stimulating factor (M‐CSF) and transforming growth factor‐beta 1 (TGF‐β1) in the presence or absence of PRF. Osteoclastogenesis was evaluated based on histochemical, gene expression, and resorption analysis. Viability was confirmed by formation of formazan crystals, live‐dead staining and caspase‐3 activity assay. Results We report here that in vitro osteoclastogenesis is greatly suppressed by soluble extracts of PRF membranes as indicated by tartrate‐resistant acid phosphatase (TRAP) staining and pit formation. In support of the histochemical observations, soluble extracts of PRF membranes decreased expression levels of the osteoclast marker genes TRAP, Cathepsin K, dendritic cell‐specific transmembrane protein (DCSTAMP), nuclear factor of activated T‐cells (NFATc1), and osteoclast‐associated receptor (OSCAR). PRF membranes, however, cannot reverse the process once osteoclastogenesis has evolved. Conclusion These in vitro findings indicate that PRF membranes can inhibit the formation of osteoclasts from hematopoietic progenitors in bone marrow cultures. Overall, our results imply that the favorable effects of PRF membranes in alveolar ridge preservation may be attributed, at least in part, by the inhibition of osteoclastogenesis.
Research Interests:
Research Interests:
Single-domain antibodies also known as nanobodies are recombinant antigen-binding domains that correspond to the heavy-chain variable region of camelid antibodies. Previous experimental studies showed that the nanobodies have stable and... more
Single-domain antibodies also known as nanobodies are recombinant antigen-binding domains that correspond to the heavy-chain variable region of camelid antibodies. Previous experimental studies showed that the nanobodies have stable and active structures at high temperatures. In this study, the thermal stability and dynamics of nanobodies have been studied by employing molecular dynamics simulation at different temperatures. Variations in root mean square deviation, native contacts, and solvent-accessible surface area of the nanobodies during the simulation were calculated to analyze the effect of different temperatures on the overall conformation of the nanobody. Then, the thermostability mechanism of this protein was studied through calculation of dynamic cross-correlation matrix, principal component analyses, native contact analyses, and root mean square fluctuation. Our results manifest that the side chain conformation of some residues in the complementarity-determining region 3 (CDR3) and also the interaction between α-helix region of CDR3 and framework2 play a critical role to stabilize the protein at a high temperature. Communicated by Ramaswamy H. Sarma.
Research Interests:
Over the recent decade, the calcium-based assays have gained much popularity in order to discover new drugs. Since breast cancer is the second cause of death in the female population, rapid and effective methods are needed to screen drug... more
Over the recent decade, the calcium-based assays have gained much popularity in order to discover new drugs. Since breast cancer is the second cause of death in the female population, rapid and effective methods are needed to screen drug compounds with fewer side effects. Human epidermal growth factor receptor 2 (HER2) increases intracellular free Ca on its signaling pathways. In the present study, BT474 cell line, which overexpresses HER2 receptor, was selected and using fura-2-AM, intracellular Ca release was investigated. The changes in the concentration of intracellular Ca were evaluated by variation in the amount of fluorescence intensity. In the presence of epidermal growth factor (EGF), an increase in fluorescence intensity was observed so that after 20 min it raised to the maximum level. After treatment of BT474 cells by lapatinib, as a tyrosine kinase inhibitor (TKI), the signaling pathway of EGFR/HER2 heterodimer was significantly inhibited, which resulted in a decrease in Ca entry into the cytoplasm and fluorescence emission decreased. The IC value for the effect of lapatinib on BT474 cells was 113.2 nmol/L. Our results suggest this method is a simple, efficient and specific approach and can potentially be useful for screening new drug candidates against EGFR/HER2 heterodimer signaling pathways. Graphical abstract ᅟ.
Research Interests:
Since anthrax is an acute infectious disease, detection and neutralization of the toxins of pathogenic Bacillus anthracis are of great importance. The critical role of protective antigen (PA) component of tripartite anthrax toxin in toxin... more
Since anthrax is an acute infectious disease, detection and neutralization of the toxins of pathogenic Bacillus anthracis are of great importance. The critical role of protective antigen (PA) component of tripartite anthrax toxin in toxin entry into the host cell cytosol provided a great deal of effort to generate monoclonal antibodies against this constitute. Regarding the importance of anthrax detection/neutralization and unique physicochemical and pharmacological features of VHHs as single domain antibodies, the present study aimed to generate VHHs against the receptor binding domain of PA, termed PAD4. After camel immunization, a gene repertoire of VHH fragments with a diversity of 4.7×108 clones was produced, followed by constructing a VHH phage display library. A stringent successive biopanning was then carried out to isolate the phages displaying high affinity VHHs against PAD4.Polyclonal and monoclonal Enzyme-linked immunosorbent assay (ELISA) verified binding specificity of...
Research Interests:
Alpha-1-antitrypsin (A1AT) is a major serum protein in human with protease inhibitory activity. Because of its extensive application in medicine, recombinant DNA technology has been considered for its production. The current study is... more
Alpha-1-antitrypsin (A1AT) is a major serum protein in human with protease inhibitory activity. Because of its extensive application in medicine, recombinant DNA technology has been considered for its production. The current study is going to examine co-expression of A1AT, and soluble domain of v-SNARE in Pichia pastoris, which can prevent the secretion of A1AT after passing the secretory pathway thoroughly. This was done mainly to preserve the biological activity of A1AT which in the secretory mode might be impaired in the fermentation and early clarification conditions. SNARE proteins are the driving force for vesicle docking and membrane fusion in the term defined as exocytosis. Intracellular expression of the cytoplasmic domain of v-SNARE and its subsequent interaction to form SNARE complex can intensify the competition for A1AT secretory vesicles to be fused and released to the media. Our investigation shows successful co-expression of A1AT in the form of post-Golgi vesicles (P...
Research Interests:
Objective:In the present work, we have extended the study and immobilized the metalloprotease enzyme in glutaraldehyde cross-linked chitosan nanogels to scrutinize the enzyme’s features including stability over its soluble free... more
Objective:In the present work, we have extended the study and immobilized the metalloprotease enzyme in glutaraldehyde cross-linked chitosan nanogels to scrutinize the enzyme’s features including stability over its soluble free form.Method:The immobilized metalloprotease was characterized using scanning electron microscopy (SEM), followed by Fourier transform infrared (FTIR) spectroscopy. The enzyme is optimally active at 50°C and pH range of 8.0–10.Results:Thermal stability of the enzyme enhanced when immobilized on the nanogel. After 5 min of incubation at 50°C, immobilized enzymes retained 60% of their original activity, while negligible activity (23%) was observed in the case of the free enzyme.Conclusion:The results obtained here provide a powerful demonstration of the benefits of taking the glutaraldehyde cross-linked chitosan matrices to enhance metalloprotease stability. The high stability of the immobilized enzyme serves to improve its performance for possible application o...
Research Interests:
Neuroserpin, a member of the Serine Proteinase Inhibitor (Serpin) superfamily, is known to be a neuroprotective factor in the focal ischemic stroke followed by reducing the microglial activation. Neuroserpin is a protein rich of... more
Neuroserpin, a member of the Serine Proteinase Inhibitor (Serpin) superfamily, is known to be a neuroprotective factor in the focal ischemic stroke followed by reducing the microglial activation. Neuroserpin is a protein rich of methionine residues that can scavenge the free radical species which may increase its neuroprotective effect. On the other hand, the oxidative modifications of the amino acid residues in neuroserpin may lead to changes in its conformation and function. In this study, it was investigated the changes in the conformation and the function of the oxidized neuroserpin. Neuroserpin expressed in E. coli, BL21 or M15 harboring plasmid pQE81L containing neuroserpin cDNA. Expressed neuroserpin was purified by resin sulfopropyl A50 precharged with 0.1 M NiSO4 under denaturing condition. Neuroserpin was oxidized under oxidative stress condition in the presence of different concentration of hydrogen peroxide. The oxidation of neuroserpin was conveniently detected by a car...
Research Interests:
... Font Size: Expression, Refolding and Angiogenic Activity of Human VEGF Receptor Binding Domain. Shirin Shahangian, Reza H. Sajedi, Kamran Mansouri, Sadegh Hasannia, Shirin Jalili. Last modified: 2012-05-13. Abstract. ...
Research Interests:
Alpha 1- antitrypsin (α1AT) a 54 kDa glycoprotein is a protease inhibitor. In the absence of α1AT, elastase released by lung macrophages, was not inhibited and lead to elastin breakdown and pulmonary problems such as emphysema or COPD.... more
Alpha 1- antitrypsin (α1AT) a 54 kDa glycoprotein is a protease inhibitor. In the absence of α1AT, elastase released by lung macrophages, was not inhibited and lead to elastin breakdown and pulmonary problems such as emphysema or COPD. α1AT has three site of N-glycosylation and a characteristic reactive central loop (RCL). As small-scale medicines are preferred for pulmonary drug delivery, in this study α1ATs (1, 2, 3, 4 and 5) were engineered and shortened from the N-terminal region. In order to investigate the effect of different mutations and the deletion of 46 amino acids theoretical studies were performed. Homology modeling was performed to generate the 3D structure of α1ATs. The 10 ns Molecular Dynamic (MD) simulations were carried out to refine the models. Results from MD and protein docking showed that α1AT2 has the highest binding affinity for neutrophil elastase, provided the basis for the experimental phase in which sequences from the five α1AT constructs were inserted in...
Research Interests: Biology, Medicine, Protein Engineering, Biological Sciences, Humans, and 11 moreComputer Simulation, Escherichia coli, Lung Diseases, Plasmids, Protein Secondary Structure Prediction, Molecular weight, Energy Transfer, Site-directed Mutagenesis, Oxidation-Reduction, Alpha-1 Antitrypsin, and binding sites
ABSTRACT We report on a method for the sensitive determination of Helicobacter that is based on fluorescence resonance energy transfer using two oligonucleotide probes labeled with CdTe quantum dots (QDs) and 5-carboxytetramethylrhodamine... more
ABSTRACT We report on a method for the sensitive determination of Helicobacter that is based on fluorescence resonance energy transfer using two oligonucleotide probes labeled with CdTe quantum dots (QDs) and 5-carboxytetramethylrhodamine (Tamra) respectively. QDs labeled with an amino-modified first oligonucleotide, and a Tamra-labeled second oligonucleotide were added to the DNA targets upon which hybridization occurred. The resulting assembly brings the Tamra fluorophore (the acceptor) and the QDs (the donor) into close proximity and causes fluorescence resonance energy transfer (FRET) to occur upon photoexcitation of the donor. In the absence of target DNA, on the other hand, the probes are not ligated, and no emission by the Tamra fluorophore is produced due to the lack of FRET. The feasibility of the method was demonstrated by the detection of a synthetic 210-mer nucleotide derived from Helicobacter on a nanomolar level. This homogeneous DNA detection scheme is simple, rapid and efficient, does not require excessive washing and separation steps, and is likely to be useful for the construction of a nanobiosensor for Helicobacter species. Graphical Abstract We report a method for the sensitive determination of Helicobacter that is based on fluorescence resonance energy transfer using two oligonucleotide probes labeled with CdTe quantum dots and 5-carboxytetramethylrhodamine respectively. The feasibility of the method was demonstrated by the detection of a synthetic 210-mer nucleotide derived from Helicobacter on a nanomolar level. This homogeneous DNA detection scheme is simple, rapid and efficient, does not require excessive washing and separation steps, and is likely to be useful for the construction of a nanobiosensor for Helicobacter species.
Research Interests:
Research Interests:
A zinc-binding protein was purified to homogeneity for the first time from the gonad parts of scallops, Patinopecten yessoensis, kept in filtered seawater to which no heavy metals were added. Based upon the elution profiles in two... more
A zinc-binding protein was purified to homogeneity for the first time from the gonad parts of scallops, Patinopecten yessoensis, kept in filtered seawater to which no heavy metals were added. Based upon the elution profiles in two chromatographic systems, spectrophotometric analysis, and amino acid composition of the purified preparation, the protein met the criteria for classification as a metallothionein; i.e., low molecular weight (about 9000), paucity of both aromatic amino acid residues and absorbance at 280 nm, and abundance of both cysteinyl residues (> 25%) and absorbance at 215 and 254 nm. Furthermore, the results of chromatographies on a Sephacryl S-300 column and electrophoresis with or without SDS suggested that the protein molecules would be in several polymeric forms in vivo. The antiserum prepared with the purified protein as the antigen was shown to have immunocross-reactivity to neither an extract of the surf clam, Pseudocardium sybillae, nor the whelk, Neptunea arthritica, indicating the...
Research Interests:
Background Alpha 1- antitrypsin (α1AT) belongs to the superfamily of serpins and inhibits different proteases. α1AT protects the lung from cellular inflammatory enzymes. In the absence of α1AT, the degradation of lung tissue results to... more
Background Alpha 1- antitrypsin (α1AT) belongs to the superfamily of serpins and inhibits different proteases. α1AT protects the lung from cellular inflammatory enzymes. In the absence of α1AT, the degradation of lung tissue results to pulmonary complications. The pulmonary route is a potent noninvasive route for systemic and local delivery. The aerosolized α1AT not only affects locally its main site of action but also avoids remaining in circulation for a long period of time in peripheral blood. Poly (D, L lactide-co glycolide) (PLGA) is a biodegradable and biocompatible polymer approved for sustained controlled release of peptides and proteins. The aim of this work was to prepare a wide range of particle size as a carrier of protein-loaded nanoparticles to deposit in different parts of the respiratory system especially in the deep lung. Various lactide to glycolide ratio of the copolymer was used to obtain different release profile of the drug which covers extended and rapid drug ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Neuroserpin, a member of the Serine Proteinase Inhibitor (Serpin) superfamily, is known to be a neuroprotective factor in the focal ischemic stroke followed by reducing the microglial activation. Neuroserpin is a protein rich of... more
Neuroserpin, a member of the Serine Proteinase Inhibitor (Serpin) superfamily, is known to be a neuroprotective factor in the focal ischemic stroke followed by reducing the microglial activation. Neuroserpin is a protein rich of methionine residues that can scavenge the free radical species which may increase its neuroprotective effect. On the other hand, the oxidative modifications of the amino acid residues in neuroserpin may lead to changes in its conformation and function. In this study, it was investigated the changes in the conformation and the function of the oxidized neuroserpin. Neuroserpin expressed in E. coli, BL21 or M15 harboring plasmid pQE81L containing neuroserpin cDNA. Expressed neuroserpin was purified by resin sulfopropyl A50 precharged with 0.1 M NiSO4 under denaturing condition. Neuroserpin was oxidized under oxidative stress condition in the presence of different concentration of hydrogen peroxide. The oxidation of neuroserpin was conveniently detected by a car...