ISSN 00062979, Biochemistry (Moscow), 2008, Vol. 73, No. 1, pp. 113. © Pleiades Publishing, Ltd., 2008. Original Russian Text © G. N. Rudenskaya, D. V. Pupov, 2008, published in Biokhimiya, 2008, Vol. 73, No. 1, pp. 317. REVIEW Cysteine Proteinases of Microorganisms and Viruses G. N. Rudenskaya1* and D. V. Pupov2 1Faculty of Chemistry and 2Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia; fax: (495) 9393181; Email:
[email protected] Received May 7, 2007 Revision received July 18, 2007 Abstract—This review considers properties of secreted cysteine proteinases of protozoa, bacteria, and viruses and presents information on the contemporary taxonomy of cysteine proteinases. Literature data on the structure and physicochemical and enzymatic properties of these enzymes are reviewed. High interest in cysteine proteinases is explained by the discovery of these enzymes mostly in pathogenic organisms. The role of the proteinases in pathogenesis of several severe diseases of human and animals is discussed. DOI: 10.1134/S000629790801001X Key words: cysteine proteinases, properties, protozoa, bacteria, viruses Classification and Catalytic Mechanism papain and related peptidases showed that the catalytic of Cysteine Proteinases residues are arranged in the following order in the polypeptide chain: Cys, His, and Asn. Also, a glutamine Cysteine proteinases are peptidyl hydrolases in residue preceding the catalytic cysteine is also important which the role of the nucleophilic group of the active site for catalysis. This residue is probably involved in the for is performed by the sulfhydryl group of a cysteine residue. mation of the oxyanion cavity of the enzyme. The cat Cysteine proteinases were first discovered and investigat alytic cysteine residue is usually followed by a residue of ed in tropic plants.