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Physicochemical properties of α- and β-fibrinogenases of Trimeresurus mucrosquamatus venom

1977; Elsevier BV; Volume: 481; Issue: 2 Linguagem: Inglês

10.1016/0005-2744(77)90295-9

1878-1454

Chaoho Ouyang, Che‐Ming Teng, Yung-Ching Chen,

Erythrocyte Function and Pathophysiology

α- and β-Fibrinogenases (EC 3.4.21.5) were purified from Trimeresurus mucrosquamatus venom by the technique of recycling chromatography. Both enzymes were single polypeptide chains and homogeneous as judged by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis and ultracentrifugation. The sedimentation constants of α- and β-fibrinogenases were 2.52 and 3.04 respectively. The molecular weight of α-fibrinogenase was 21 500–23 400, and that of β-fibrinogenase was 25 000–26 000. The contents of proline, glycine and tryptophan were higher in β-fibrinogenase than in α-fibrinogenase. The isoelectric points of α- and β-fibrinogenases were pH 8.1 and 5.7 respectively. The optimal pH of α-fibrinogenase was about 7.4 and that of β-fibrinogenase was around 8.5. The activity of α-fibrinogenase was completely destroyed after 30 min at 60°C, pH 5.6, 7.4 and 9.0, while that of β-fibrinogenase was not significantly affected by the same treatment. Both enzymes showed proteolytic activities toward fibrinogen and casein, but were devoid of phospholipase A, alkaline phosphomonoesterase and phosphodiesterase activities of the crude venom. The tosyl-l-arginine methylester esterase activity of β-fibrinogenase was about 17 times that of the crude venom, while α-fibrinogenase was completely devoid of this activity. The fibrinogenolytic activity of α-fibrinogenase was markedly inhibited by EDTA and cysteine, while that of β-fibrinogenase was inhibited markedly by phenylmethane sulfonylfluoride and slightly by tosyl-l-lysine chloromethylketone and cysteine.