Complement components corresponding to mammalian C8 and C9 were isolated from carp (Cyprinus carpio) serum. Carp C8 (M(r) 146,000) proved to be a γ-globulin composed of three polypeptide chains (α-chain, M(r) 62,000; β-chain, M(r) 62,000; γ-chain, M(r) 22,000). The α-chain was disulfide-linked to the γ-chain and the β-chain was non-covalently associated with the α-γ chain, in fair agreement with mammalian C8. However, the N-terminal amino acid sequences of the three subunits showed no homology with those of human C8. Carp C9 was an α-globulin composed of a single polypeptide (M(r) 91,000) and the N-terminus was blocked. Carp serum depleted of C8 did not hemolyse either carp antibody-sensitized sheep erythrocytes or non-sensitized rabbit erythrocytes, while C9-depleted carp serum did not hemolyse the former, but did hemolyse the latter target cells, as in the case of C9-depleted human serum. Copyright (C) 1996 Elsevier Science Ltd.
All Science Journal Classification (ASJC) codes
- Molecular Biology