title: Cleavage of the complement system C3 component by HIV-1 proteinase.
abstract: The C3 factor of the complement system and its C3b fragment are cleaved in vitro by the proteinase of the human immunodeficiency virus, type 1 (HIV PR). The cleavage occurs in the alpha-chain of both substrates at multiple sites yielding a 100 kDa fragment of the C3 alpha-chain and multiple fragments of the C3b alpha-chain. The scissile bonds are: Ala86-Glu87, Leu310-Leu311, His641-Trp642 and Arg649-Ser650. The resulting fragments resemble the physiologically occurring inactive fragments of C3: C3c and C3d, suggesting a possible biological role of the HIV-proteinase in the complement inactivation process.
authors.affiliation: Max von Pettenkofer-Institute, Munich, Germany.
authors.forename: A F
authors.initials: AF
authors.lastname: Kisselev
authors.forename: R
authors.initials: R
authors.lastname: Mentele
authors.forename: K
authors.initials: K
authors.lastname: von der Helm
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001665:Binding Sites; D003167:Complement Activation / Q000187:drug effects / Q000235:genetics; D003176:Complement C3 / Q000378:metabolism*; D003179:Complement C3b / Q000235:genetics / Q000378:metabolism*; D015932:Complement C3c / Q000235:genetics / Q000378:metabolism*; D015933:Complement C3d / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D016333:HIV Protease / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008970:Molecular Weight
chemical_list: D000596:Amino Acids; D003176:Complement C3; D003179:Complement C3b; D015932:Complement C3c; D015933:Complement C3d; D016333:HIV Protease