Primary structure of human C-reactive protein.

Abstract
The complete amino acid sequence of human C-reactive protein was established. Distant homologies to the C3 [complement component 3] homology region in the CH2 [H chain constant region 2] domain of Ig [immunoglobulin] G and to C3a anaphylotoxin were noted. No homology to other Ig homology regions or to the same homology region in other H chains were observed. The previously reported homologies between rabbit and human C-reactive protein and protein Clt [t fragment of complement component 3] were extended and strengthened.