Venom from southern copperhead snake (Agkistrodon Contortrix Contortrix). I. Characterization of a protease that preferentially releases fibrinopeptide B

Toxicon ◽  
1987 ◽  
Vol 25 (7) ◽  
pp. 751-757 ◽  
Author(s):  
Akira Shimizu ◽  
Elsie C. Jimenez ◽  
Junichi Takagi ◽  
Yuji Inada ◽  
Yuji Saito
1987 ◽  
Author(s):  
Carolyn L Orthner ◽  
Prabir Bhattacharya ◽  
Dudley K Strikland

There are two recent reports on the purification and properties of a protein C activator (PCA) from the venom of the Southern copperhead snalce. The purification of a 37,000 Mr nonenzymatic PCA (Martinoli and Stocker, Thrcmb. Res. 43, 253, 1976) as well as of a 20,000 Mr thrombin-like enzyme (Klein and Walker, Biochem. ,25, 4175, 1986) have been described. The purpose of this investigation was to purify and further characterize the PCA(s) from this vencm. A PCA has been isolated by sulphopropyl-Sephadex followed by gel filtration chromatography resulting in approximately a 100-fold purification with a 50% yield. PCA appeared as a single band on SDS-PAGE with an estimated Mr of 32,000 or 37,000 in the absence or presence of β-mercaptoethanol, respectively. High pressure gel permeation cinematography of PCA in Tris-buffered saline, pH 7.5 resulted in a single protein peak with a Mr of 39,000 which was coincident with activity. PCA was a potent activator of human protein C (PC) with a Km for PC of 0.6uM and a Vm of 0.02 sec-1. In addition, PCA catalyzed the arnidolysis of Tosyl-gly-pro-arg-p-nitroanilide (TGPRpNA) with a Km of 1.1 irM and a Vim of 66 sec-1. The rate of arnidolysis of five other pept idyl-arginyl-pNA substrates each tested at 1.0 mM was < 10% that of TGPRpNA. PCA was inhibited by nitrophenylguanidi-nobenzoate (NPGB), phenylmethylsulphonylflouride, D-phe-pro-arg-chloromethyi_ketone (PPACK) and soybean trypsin inhibitor indicating that PCA is a serine protease. The active site concentration of PCA as measured by NPGB titration was 90% that of the protein concentration. Measurement of the rate of PCA inhibition at varying levels of PPACK indicated that it had a Ki of 34uM .and an aUcylation rate constant of 0.09 min-1. PCA activation of PC was completely inhibited by CaC12 with an apparent Ki of 99uM. Since neither PCA arnidolysis of TGPRpNA nor inhibition by PPACK was affected by Ca2+, the effect of this metal was likely on the substrate PC. In summary, a PCA has been purified to homogeneity and has properties which are distinct from those reported. PCA premises to be a useful enzyme in studies of PC and its activation.


1984 ◽  
Vol 224 (1) ◽  
pp. 301-307 ◽  
Author(s):  
T K Gartner ◽  
M L Ogilvie

Three lactose-inhibited lectins from the venoms of the snakes Agkistrodon contortrix contortrix (southern copperhead), Ancistrodon piscivorous leukostoma (western cottonmouth moccasin) and Crotalus atrox (western diamondback rattlesnake) have been isolated and newly characterized. The three lectins are similar to thrombolectin, a lectin isolated from the venom of Bothrops atrox (fer-de-lance) (Gartner, Stocker & Williams, 1980), with regard to sugar specificity, Mr, Ca2+ requirements and sensitivity to reducing agents. Each lectin is a dimer (Mr 28 000) consisting of monomers (Mr 14 000) indistinguishable on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Haemagglutination activity is dependent on the presence of Ca2+ and is inhibited by reducing agents. The lectins are not identical and can be distinguished on the basis of relative affinities for inhibiting sugars, isoelectric points and immunoprecipitation assays using anti-(cottonmouth lectin) serum.


Biochemistry ◽  
1988 ◽  
Vol 27 (7) ◽  
pp. 2558-2564 ◽  
Author(s):  
Carolyn L. Orthner ◽  
Prabir Bhattacharya ◽  
Dudley K. Strickland

1987 ◽  
Vol 262 (26) ◽  
pp. 12607-12613 ◽  
Author(s):  
W Kisiel ◽  
S Kondo ◽  
K J Smith ◽  
B A McMullen ◽  
L F Smith

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