Biomaterial Database

Primary structure of human C-reactive protein. 1979

E B Oliveira, and C Gotschlich, and T Y Liu

The complete amino acid sequence has been derived for human C-reactive protein (CRP). The protein yielded a unique sequence containing 187 amino acids in a single polypeptide chain. The NH2-terminal residue of CRP is pyrrolidonecarboxylic acid and the COOH terminus is proline. The 2 half-cystine residues at positions 36 and 78 are involved in a disulfide bond. Based on the amino acid composition derived from the sequence data, a minimal molecular weight of 20,946 has been calculated for human CRP. This value agrees well with the molecular weight of 21,500 established by gel filtration of CRP in 5.0 M guanidine Cl (Gotschlich, E.C., and Edelman, G.M. (1965) Proc. Natl. Acad. Sci. U.S.A. 54, 558--566). The primary structure of human CRP has been examined for internal homology and compared to all known proteins whose structures were published before April, 1978 by two computer programs; program SEARCH and program RELATE (Dayhoff, M. O., ed (1976) in Atlas of Protein Sequence and Structure, Vol. 5, Suppl. 2, pp. 3--8, National Biomedical Research Foundation, Silver Spring, MD). The computer analyses showed no significant repeating sequences within the C-reactive protein molecule. This observation seems to rule out the possibility of gene duplication in the evolution of this protein. Distant homologies, which were statistically insignificant, have been noted to the CH2 domain of immunoglobulin G (IgG) and to C3a anaphylotoxin. The homologie noted are insufficient to support a common evolutionary origin of these proteins. No homology region in other heavy chains was observed. It is therefore preferable, at this point in time, to assign CRP and the protein known as 9.5 S alpha-glycoprotein, P component, and Clt to a new super family unrelated to any other proteins investigated. The homology between these proteins was demonstrated previously (Osmand, A.P., Friedenson, B., Gewurz, H., Painter, R.H., Hofmann, T., and Shelton, E. (1977) Proc. Natl. Acad. Sci. U.S.A. 74, 739--743) on the basis of sequence data on approximately 20 NH2-terminal residues of rabbit C-reactive protein, of Clt, and a cyanogen bromide fragment of human CRP.

UI	MeSH Term	Description	Entries
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D010450	Endopeptidases	A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.	Endopeptidase,Peptide Peptidohydrolases
D002097	C-Reactive Protein	A plasma protein that circulates in increased amounts during inflammation and after tissue damage. C-Reactive Protein measured by more sensitive methods often for coronary heart disease risk assessment is referred to as High Sensitivity C-Reactive Protein (hs-CRP).	High Sensitivity C-Reactive Protein,hs-CRP,hsCRP,C Reactive Protein,High Sensitivity C Reactive Protein
D003488	Cyanogen Bromide	Cyanogen bromide (CNBr). A compound used in molecular biology to digest some proteins and as a coupling reagent for phosphoroamidate or pyrophosphate internucleotide bonds in DNA duplexes.	Bromide, Cyanogen
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino