Inhibition of the protein C activator ProtacR, a serine proteinase from the venom of the southern copperhead snake Agkistrodon contortrix contortrix

Toxicon ◽  
1991 ◽  
Vol 29 (2) ◽  
pp. 151-155 ◽  
Author(s):  
J. Stürzebecher ◽  
U. Neumann ◽  
J. Meier
Keyword(s):  
Protein C ◽  
Serine Proteinase ◽  
Agkistrodon Contortrix ◽  
Agkistrodon Contortrix Contortrix

Primary structure of a protein C activator from Agkistrodon contortrix contortrix venom

Biochemistry ◽  
1989 ◽  
Vol 28 (2) ◽  
pp. 674-679 ◽  
Author(s):  
Brad A. McMullen ◽  
Kazuo Fujikawa ◽  
Walter Kisiel
Keyword(s):  
Primary Structure ◽  
Protein C ◽  
Agkistrodon Contortrix ◽  
Agkistrodon Contortrix Contortrix

PURIFICATION AND CHARACTERIZATION OF A PROTEIN C ACTIVATOR FROM THE VENOM OF AGKISTRODON CONTORTRIX CONTORTRIX

1987 ◽  
Author(s):  
Carolyn L Orthner ◽  
Prabir Bhattacharya ◽  
Dudley K Strikland
Keyword(s):  
Protein C ◽  
Protein Concentration ◽  
Gel Filtration ◽  
Purification And Characterization ◽  
Agkistrodon Contortrix ◽  
Purification And Properties ◽  
Sds Page ◽  
Single Protein ◽  
Agkistrodon Contortrix Contortrix

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.

Characterisation and Some Properties of the Protein C Activator from Agkistrodon Contortrix Contortrix Venom

1988 ◽  
Vol 59 (01) ◽  
pp. 040-044 ◽  
Author(s):  
Thomas Exner ◽  
Riita Vaasjoki
Keyword(s):  
Protein C ◽  
Anticoagulant Activity ◽  
Activated Protein C ◽  
Apparent Molecular Weight ◽  
Single Chain ◽  
Crude Venom ◽  
Agkistrodon Contortrix ◽  
Normal Plasma ◽  
Agkistrodon Contortrix Contortrix ◽  
Contact Mechanism

SummaryThe protein C activator (PCA) detectable in the venom of Agkistrodon Contortrix Contortrix (ACCV, Southern Copperhead) by specific immunochromometric assay and anticoagulant activity has been isolated and partially characterized. Chromatog raphy of the crude venom on SP-Sephadex followed by Con A Sepharose and finally on hydroxylapatite was necessary to achieve an electrophoretically – pure product. The isolated PCA is a single chain glycoprotein with strong positive charge and an apparent molecular weight of 36,000.It had an immediate-inhibiting effect on the activated partial thromboplastin time (APTT) of normal plasma with no noticeable eilect Oii the piOtliiumbm time, its piolonging eifect oil the APTT was dependent on protein C and il appeared to interfere with the contact mechanism rather than with factors V and VIII. It had enzymatic activity on some tripeptide chromogenic substrates sensitive to thrombin and kallikrein. When mixed with normal plasma it generated activity on substrates sensitive to activated protein C and should be useful for studies of protein C.

Characterization of a protein C activator from the venom of Agkistrodon contortrix contortrix

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

scholarly journals Characterization of a protein C activator from Agkistrodon contortrix contortrix venom.

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

The action of a fibrin-promoting enzyme from the venom of Agkistrodon contortrix contortrix on rat fibrinogen and plasma

Toxicon ◽  
1990 ◽  
Vol 28 (11) ◽  
pp. 1364-1367 ◽  
Author(s):  
Jan E. Dyr ◽  
Jiří Suttnar ◽  
Jan Šimák ◽  
Hana Fořtová ◽  
František Kornalík
Keyword(s):  
Agkistrodon Contortrix ◽  
Agkistrodon Contortrix Contortrix
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