TY - JOUR
AU - Iwanaga,, Sadaaki
AB - Abstract A hemorrhagic protein (60 kDa), HR1B, present in the venom of Trimeresurus flavoviridis is a mosaic protein consisting of an NH2 -terminal metalloproteinase-domain, a disintegrin (platelet aggregation inhibitor)-like domain, and a unique COOH-tenninal Cys-rich domain. Since the gross structures of HR1B and protein precursors of disintegrins, trigramin, and rhodostomin, all of which contain the metalloproteinase domain, aresimilar, many disintegrins so far detected in snake venoms are assumed to be autoproteolytic fragments released from precursors. In ongoing related experiments, the newly purified hemorrhagic metalloproteinases, HR1A from T. flavoviridis venom and HT-1 from Crotalus ruber ruber venom, in addition to HR1B, were autoproteolyzed, in the absence of Ca2+, at 37C for 3-12h. Under these conditions, HR1A, HR1B, and HT-1 each released a single major fragment of 32, 34, and 31 kDa, respectively. The entire amino acid sequences of the isolated fragments indicated the presence of disintegrin-like and Cys-rich domains in the COOH-terminal regions of HR1A, HR1B, and HT-1, respectively. It seems likely that so-called disintegrins probably originate from various metalloproteinases present in venom. On the bases of peptide sequences close to the autoproteolytic cleavage sites of these metalloproteinases and the sites of fibrinogen cleaved by these enzymes, we synthesized new intramolecularly quenched fluorogenic peptide substrates. Among the 10 peptides tested, 2-aminobenzoyl (Abz)-Ser-Pro-Met-Leu-2,4-dinitroanilinoethylamide (Dna) proved to be the best substrate for venom metalloproteinase, as deduced from kinetic analyses. This content is only available as a PDF. Author notes 1This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Sciences and Culture of Japan. Portions of this paper (including “ MATERIALS AND METHODS, ” and Tables IS-VS and Figs 1S-5S) are presented in miniprint at the end of this paper. 2Present address: Department of Molecular Biology, Mie University School of Medicine, Tsu, Mie 514. 1993 © BY THE JOURNAL OF BIOCHEMISTRY
TI - Primary Structures of Platelet Aggregation Inhibitors (Disintegrinis) Autoproteolytically Released from Snake Venom Hemorrhagic Metalloproteinases and New Flurogenic Peptide Subtrates for These Enzymes
JO - The Journal of Biochemistry
DO - 10.1093/oxfordjournals.jbchem.a124069
DA - 1993-04-01
UR - https://www.deepdyve.com/lp/oxford-university-press/primary-structures-of-platelet-aggregation-inhibitors-disintegrinis-IZE0EajCLB
SP - 473
EP - 483
VL - 113
IS - 4
DP - DeepDyve
ER -