1op2
Crystal Structure of AaV-SP-II, a Glycosylated Snake Venom Serine Proteinase from Agkistrodon acutus
OverviewOverview
We deduced that Agkistrodon actus venom serine proteinases I and II, previously isolated from the venom of A. acutus (Zhu, Z., Gong, P., Teng, M., and Niu, L. (2003) Acta Crystallogr. Sect. D Biol. Crystallogr. 59, 547-550), are encoded by two almost identical genes, with only the single substitution Asp for Asn at residue 62. Amidolytic assays indicated that they possess slightly different enzymatic properties. Crystal structures of A. actus venom serine proteinases I and II were determined at resolution of 2.0 and 2.1 A with the identification of trisaccharide (NAG(301)-FUC(302)-NAG(303)) and monosaccharide (NAG(301)) residues in them, respectively. The substrate binding sites S3 of the two proteinases appear much shallower than that of Trimeresurus stejnegeri venom plasminogen activator despite the overall structural similarity. Based on structural analysis, we showed that these Asn(35)-linked oligosaccharides collide spatially with some inhibitors, such as soybean trypsin inhibitor, and would therefore hinder their inhibitory binding. Difference of the carbohydrates in both the proteinases might also lead to their altered catalytic activities.
About this StructureAbout this Structure
1OP2 is a Single protein structure of sequence from Deinagkistrodon acutus. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures and amidolytic activities of two glycosylated snake venom serine proteinases., Zhu Z, Liang Z, Zhang T, Zhu Z, Xu W, Teng M, Niu L, J Biol Chem. 2005 Mar 18;280(11):10524-9. Epub 2005 Jan 4. PMID:15632114 Page seeded by OCA on Sat May 3 04:06:57 2008