Identification of amino acid residues of abrin-a A chain is essential for catalysis and reassociation with abrin-a B chain by site-directed mutagenesis
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Identification of amino acid residues of abrin-a A chain is essential for catalysis and reassociation with abrin-a B chain by site-directed mutagenesis.
Abrin is a toxic protein consisting of two subunits, an enzymatic A chain (ABRaA) and a lectin-active B chain (ABRaB), linked by a disulfide bond. Site-directed mutagenesis was performed using PCR to study how the conserved amino acid residues, Tyr74, Tyr113, Glu164 and Trp198, around the active site of ABRaA are involved in enzyme catalysis, enzyme-substrate recognition and reassociation of AB...
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By site-directed mutagenesis on human cytidine deaminase (CDA), five mutant proteins were obtained: C65A, C99A, C102A, E67D and E67Q. The three cysteine mutants were completely inactive, whereas E67D and E67Q showed a specific activity about 200- and 200000-fold lower, respectively, than the wild-type CDA. Zinc analysis revealed that only E67D, E67Q and C65A contained 1 mol Zn2+/mol subunit as ...
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Plant ribosome-inactivating proteins (RIPs) are RNA N-glycosidases that inhibit protein synthesis in cells. Abrin, a type II RIP, is an AB type toxin, which is one of the most lethal types of toxin known. The B chain facilitates the entry of the molecule into the cell, whereas the A chain exerts the toxic effect. We have generated hybridomas secreting antibodies of the immunoglobulin G class sp...
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A panel of immunotoxins was constructed by chemically attaching the ribosome-inactivating proteins abrin A chain, ricin A chain, gelonin, and momordin to the monoclonal mouse IgG2a antibody Fib75 by means of a disulfide linkage. All the immunotoxins were toxic in tissue culture to the I.I human bladder carcinoma cell line expressing the antigen recog nized by Fib75, inhibiting the incorporation...
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ژورنال
عنوان ژورنال: Protein Engineering Design and Selection
سال: 1997
ISSN: 1741-0126,1741-0134
DOI: 10.1093/protein/10.7.827