Comparison of textilinin-1 with aprotinin as serine protease inhibitors and as antifibrinolytic agents.
Textilinin-1 (Q8008) was isolated from the venom of the Pseudonaja textilis and has a 47% sequence identity to the antihaemorrhagic therapeutic agent aprotinin. When equimolar concentrations of enzyme and aprotinin were pre-incubated, plasmin was inhibited 100%, plasma kallikrein 58%, and tissue kallikrein 99%. Under the same conditions, textilinin-1 inhibited plasmin 98%, plasma kallikrein 16% and tissue kallikrein 17%. Whole blood clot lysis was inhibited strongly by both aprotinin and textilinin-1, as shown by thrombelastography. At 2 microM inhibitor lysis initiated by t-PA was greater than 99% inhibited by aprotinin (LY60 = 0.4 +/- 0.1) whereas textilinin-1, inhibited lysis by 91% (LY60 = 8.9 +/- 0.7). The same trend was found with the lysis of euglobulin fractions. From these data textilinin-1 appears to be a more specific plasmin inhibitor than aprotinin but aprotinin inhibits clot lysis to a greater extent.
Flight
Simone
S
School of Medicine, University of Queensland, Princess Alexandra Hospital, Brisbane, Australia.
Johnson
Lambro
L
Trabi
Manuela
M
Gaffney
Patrick
P
Lavin
Martin
M
de Jersey
John
J
Masci
Paul
P
D000818:Animals; D000933:Antifibrinolytic Agents / Q000494:pharmacology*; D007611:Aprotinin / Q000494:pharmacology*; D004546:Elapid Venoms / Q000494:pharmacology*; D005341:Fibrinolysin / Q000037:antagonists & inhibitors; D006801:Humans; D020842:Plasma Kallikrein / Q000037:antagonists & inhibitors; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D012910:Snake Venoms; D013916:Thrombelastography; D020840:Tissue Kallikreins / Q000037:antagonists & inhibitors
D000933:Antifibrinolytic Agents; D004546:Elapid Venoms; D015842:Serine Proteinase Inhibitors; D012910:Snake Venoms; C413544:textilinin; D007611:Aprotinin; D020842:Plasma Kallikrein; D020840:Tissue Kallikreins; D005341:Fibrinolysin