1H NMR sequential assignments and secondary structure analysis of human fibrinogen gamma-chain C-terminal residues 385-411.
The human fibrinogen gamma-chain, C-terminal fragment, residues 385-411, i.e., KIIPFNRLTIGEGQQHHLGGAKQAGDV, contains two biologically important functional domains: (1) fibrinogen gamma-chain polymerization center and (2) platelet receptor recognition domain. This peptide was isolated from cyanogen bromide degraded human fibrinogen and was investigated by 1H NMR (500 MHz) spectroscopy. Sequence-specific assignments of NMR resonances were obtained for backbone and side-chain protons via analysis of 2D NMR COSY, double quantum filtered COSY, HOHAHA, and NOESY spectra. The N-terminal segment from residues 385-403 seems to adopt a relatively fixed solution conformation. Strong sequential alpha CH-NH NOESY connectivities and a continuous run of NH-NH NOESY connectivities and several long-lived backbone NH protons strongly suggest the presence of multiple-turn or helix-like structure for residues 390 to about 402. The conformation of residues 403-411 seems to be much less constrained as evidenced by the presence of weaker and sequential alpha CH-NH NOEs, the absence of sequential NH-NH NOEs, and the lack of longer lived amides. Chemical shifts of resonances from backbone and side-chain protons of the C-terminal dodecapeptide, residues 400-411, differ significantly from those of the parent chain, suggesting that some preferred C-terminal conformation does exist.
Mayo
K H
KH
Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122.
Burke
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C
Lindon
J N
JN
Kloczewiak
M
M
D000595:Amino Acid Sequence; D003903:Deuterium; D005340:Fibrinogen; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D011487:Protein Conformation; D013329:Structure-Activity Relationship
D005340:Fibrinogen; D003903:Deuterium