Inhibition of a snake venom hemorrhagic metalloproteinase by human and rat alpha-macroglobulins.
Jararafibrase I is a hemorrhagic metalloproteinase purified from Bothrops jararaca venom, which induces local hemorrhage by degrading the basement membrane components. The present study was undertaken to investigate the inhibition of jararafibrase I by human and rat serum proteinase inhibitors. The proteolytic activity of jararafibrase I was completely inhibited by human and rat sera. In particular, rat serum displayed a greater inhibitory capacity. The inhibitory capacities of both sera were dependent on alpha-macroglobulins. SDS-PAGE analysis revealed that jararafibrase I formed complexes with alpha-macroglobulins that were present in normal sera. The proteolytic activity of jararafibrase I was completely inhibited by alpha1-macroglobulin and murinoglobulin in rat serum, and by human alpha2-macroglobulin. The inhibition molar ratios of alpha-macroglobulin/jararafibrase I were 1.5 for rat alpha1-macroglobulin and human alpha2-macroglobulin, and 2.4 for rat murinoglobulin. SDS-PAGE under reducing conditions demonstrated that the bait region of human alpha2-macroglobulin and rat murinoglobulin was cleaved by jararafibrase I. The bait region cleavage sites were identified as being situated at the 696Arg-697Leu peptide bond in human alpha2-macroglobulin, and at the 686Ala-687Val peptide bond in rat murinoglobulin.
Department of Physiology, Miyazaki Medical College, Kiyotake, Japan.
K
K
Anai
M
M
Sugiki
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E
Yoshida
M
M
Maruyama
D000595:Amino Acid Sequence; D000818:Animals; D000933:Antifibrinolytic Agents / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005343:Fibrinolytic Agents; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D006868:Hydrolysis; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors*; D051381:Rats; D012604:Scorpion Venoms / Q000737:chemistry / Q000633:toxicity*; D012910:Snake Venoms / Q000201:enzymology*; D000511:alpha-Macroglobulins / Q000737:chemistry / Q000494:pharmacology*
D000933:Antifibrinolytic Agents; D004791:Enzyme Inhibitors; D005343:Fibrinolytic Agents; C114938:Lqh II toxin; C114939:Lqh III toxin; D012604:Scorpion Venoms; D012910:Snake Venoms; D000511:alpha-Macroglobulins; D008666:Metalloendopeptidases; C076581:jararafibrase I