D. Park et al., EXPRESSION AND CHARACTERIZATION OF A NOVEL PLASMINOGEN-ACTIVATOR FROMAGKISTRODON HALYS VENOM, Toxicon (Oxford), 36(12), 1998, pp. 1807-1819
A venom gland cDNA library of Agkistrodon halys was constructed and sc
reened with a probe based on the consensus sequence of venomic serine
proteases. Next, we determined the sequences of the entire open readin
g frames of two selected positives which were found to encode novel se
rine proteases of 234 and 233 amino acids in length and named as Haly-
PA and Haly 2, respectively. Upon protein data base search, Haly-PA sh
owed the highest similarity of 82% to the previously characterized pla
sminogen activator, TSV-PA (Zhang et al. 1995, J. Biol. Chem., 270, 10
246-10255). Haly 2 displayed a 78% similarity to beta-fibrinogenase (H
ung et al. 1994, B. B. R. C., 205, 1707-1715). Haly-PA was successfull
y expressed using the baculovirus system and secreted into the culture
media as a 32 kDa glycoprotein. In the western analysis of snake veno
m, anti-Haly-PA antibody detected the same size of band indicating tha
t this enzyme is a component of snake venom. Recombinant Haly-PA was p
urified to homogeneity using the combination of anion exchange and gel
filtration column. In the fibrino(geno)lytic assay, recombinant Haly-
PA displayed an indirect fibrino(geno)lytic activity depending on the
presence of plasminogen and cleaved the plasminogen to generate the ac
tive plasmin. These results indicate that Haly-PA is a plasminogen act
ivator and displays fibrino(geno)lytic activity through conversion of
plasminogen to plasmin. (C) 1998 Elsevier Science Ltd. All rights rese
rved.