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    Catherine Schein

    cDNA was prepared from induced leukocyte poly(A) RNA and cloned in Escherichia coli. Interferon (IFN)-alpha cDNA clones were isolated by subculture cloning using a translation hybridization assay. Definitive identification of the clones... more
    cDNA was prepared from induced leukocyte poly(A) RNA and cloned in Escherichia coli. Interferon (IFN)-alpha cDNA clones were isolated by subculture cloning using a translation hybridization assay. Definitive identification of the clones was based on the production of an interferon-like protein by the transformed bacteria. Different IFN-alpha cDNAs, with characteristic target cell specificities, were identified. The cloned cDNAs typically encode a mature polypeptide of 166 (or, in the case of IFN-alpha 2, 165) amino acids and a signal sequence of 23 amino acids.
    the interaction of membrane-bound phosphoinositides with three clinically significant human inositol polyphosphate 5-phosphatases (I5Ps). A comparison to the structures determined with soluble substrates revealed differences in the... more
    the interaction of membrane-bound phosphoinositides with three clinically significant human inositol polyphosphate 5-phosphatases (I5Ps). A comparison to the structures determined with soluble substrates revealed differences in the binding mode
    and suggested how the I5Ps and apurinic endonuclease (APE1) activities evolved from the same metal-binding
    active center.
    A
    Research Interests:
    Research Interests:
    Page 1. PROTEIN AGGREGATION AND PRECIPITATION, MEASUREMENT AND CONTROL CATHERINE H. SCHEIN Structural Biology, University of Texas Medical Branch, Galveston, Texas INTRODUCTION Proteins in solution exist in a precarious equilibrium. ...
    Apurinic/apyrimidinic endonuclease 1 (APE1), a central enzyme in the base excision repair pathway, cleaves damaged DNA in Mg(2+) dependent reaction. Despite characterization of nine X-ray crystallographic structures of human APE1, in some... more
    Apurinic/apyrimidinic endonuclease 1 (APE1), a central enzyme in the base excision repair pathway, cleaves damaged DNA in Mg(2+) dependent reaction. Despite characterization of nine X-ray crystallographic structures of human APE1, in some cases, bound to various metal ions and substrate/product, the position of the metal ion and its stoichiometry for the cleavage reaction are still being debated. While a mutation of the active site E96Q was proposed to eliminate Mg(2+) binding at the "A" site, we show experimentally that this mutant still requires Mg(2+) at concentration similar to that for the wild type enzyme to cleave the AP site in DNA. Molecular dynamics simulations of the wild type APE1, E96Q and a double missense mutant E96Q + D210N indicate that Mg(2+) placed at the A-site destabilizes the bound AP site-containing DNA. In these simulations, the H-bond chain D238-H309-AP site oxygen is broken and the substrate DNA is shifted away from its crystal structure position (1DE9). In contrast, simulations with the Mg(2+) at site B or A+B sites leave the substrate DNA at the position shown in the crystal structure (1DE9). Taken together our MD simulations and biochemical analysis suggests that Mg(2+) binding at the B site is involved in the reaction mechanism associated with endonuclease function of APE1.
    In this issue of Structure, Trésaugues and colleagues determined the interaction of membrane-bound phosphoinositides with three clinically significant human inositol polyphosphate 5-phosphatases (I5Ps). A comparison to the structures... more
    In this issue of Structure, Trésaugues and colleagues determined the interaction of membrane-bound phosphoinositides with three clinically significant human inositol polyphosphate 5-phosphatases (I5Ps). A comparison to the structures determined with soluble substrates revealed differences in the binding mode and suggested how the I5Ps and apurinic endonuclease (APE1) activities evolved from the same metal-binding active center.
    ABSTRACT
    Bovine pancreatic ribonuclease A interacts with RNA along multiple binding subsites that essentially recognize the negatively charged phosphates of the substrate. This work gives additional strong support to the existence of the... more
    Bovine pancreatic ribonuclease A interacts with RNA along multiple binding subsites that essentially recognize the negatively charged phosphates of the substrate. This work gives additional strong support to the existence of the postulated phosphate-binding subsite p2 (Parés, X., Llorens, R., Arús, C., and Cuchillo, C. M. (1980) Eur. J. Biochem. 105, 571-579) and confirms the central role of Lys-7 and Arg-10 in establishing an electrostatic interaction with a phosphate group of the substrate. The effects of charge elimination by Lys-7-->Gln (K7Q) and/or Arg-10-->Gln (R10Q) substitutions in catalytic and ligand-binding properties of ribonuclease A have been studied. The values of Km for cytidine 2',3'-cyclic phosphate and cytidylyl-3',5'-adenosine are not altered but are significantly increased for poly(C). In all cases, kcat values are lower. Synthetic activity, i.e. the reversion of the transphosphorylation reaction, is reduced for K7Q and R10Q mutants and is ...
    The degree of oligomerization (or in some cases aggregation) often determines the physiological half-life and uptake rate of a protein preparation. High-resolution crystal structures of insulin and other pharmacologically interesting... more
    The degree of oligomerization (or in some cases aggregation) often determines the physiological half-life and uptake rate of a protein preparation. High-resolution crystal structures of insulin and other pharmacologically interesting proteins have aided in the design of mutants with altered quaternary structure and physiological uptake rates. Analysis of the contacts between natural oligomers and protein complexes can indicate sequences that may enhance protein oligomerization. These sequences can be altered to produce monomeric protein.
    This review deals with ways of stabilizing proteins against aggregation and with methods to determine, predict, and increase solubility. Solvent additives (osmolytes) that stabilize proteins are listed with a description of their effects... more
    This review deals with ways of stabilizing proteins against aggregation and with methods to determine, predict, and increase solubility. Solvent additives (osmolytes) that stabilize proteins are listed with a description of their effects on proteins and on the solvation properties of water. Special attention is given to areas where solubility limitations pose major problems, as in the preparation of highly concentrated solutions of recombinant proteins for structural determination with NMR and X-ray crystallography, refolding of inclusion body proteins, studies of membrane protein dynamics, and in the formulation of proteins for pharmaceutical use. Structural factors relating to solubility and possibilities for protein engineering are analyzed.
    The UV-light damage specific DNA glycosylase from Chlorella virus strain PBCV-1 (pyrimidine dimer glycosylase; PDG) incises DNA at sites containing UV-induced thymidine dimers by catalyzing the breakage of the N-C-1′ glycosyl bond. As the... more
    The UV-light damage specific DNA glycosylase from Chlorella virus strain PBCV-1 (pyrimidine dimer glycosylase; PDG) incises DNA at sites containing UV-induced thymidine dimers by catalyzing the breakage of the N-C-1′ glycosyl bond. As the amino acid sequence of PDG is 41% identical to that of T4 endonuclease V (Endo V), and potential key active site residues are conserved, we used
    Research Interests:
    Research Interests:
    ... Fleischer et al., 2004; Sicherer, 2003) and will face a life of careful avoidance of all potential sources of eliciting Catherine H. Schein, Ovidiu Ivanciuc, and ... O64943 165 229.0 2.7 e− 62 2 Olee8 Q9M7R0 171 89.8 2.2 e− 20 4 Syrv3... more
    ... Fleischer et al., 2004; Sicherer, 2003) and will face a life of careful avoidance of all potential sources of eliciting Catherine H. Schein, Ovidiu Ivanciuc, and ... O64943 165 229.0 2.7 e− 62 2 Olee8 Q9M7R0 171 89.8 2.2 e− 20 4 Syrv3 P58171 81 62.5 1.7 e− 12 5 Bran 2 BAA09633 ...
    Background: Cedar pollens cause allergic disease in diverse geographic areas. We have recently purified and characterized the major mountain cedar (Juniperus ashei) pollen allergen, Jun a 1. Objective: A full-length complementary DNA for... more
    Background: Cedar pollens cause allergic disease in diverse geographic areas. We have recently purified and characterized the major mountain cedar (Juniperus ashei) pollen allergen, Jun a 1. Objective: A full-length complementary DNA for Jun a 1 was cloned and sequenced, and the recombinant protein was expressed. Methods: Messenger RNA from mountain cedar pollen was purified and Jun a 1 sequences
    ABSTRACT

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