title: Functionally important residues for the anticoagulant activity of a basic phospholipase A(2) from the Agkistrodon halys pallas.
abstract: To identify the anticoagulant region of the phospholipase A(2) (PLA(2)) from the Agkistrodon halys Pallas (class II), four mutants E53G, W70M, T56K, and D67K were produced according to the prediction from the crystal structure and the sequence comparison of the strong, weak and non-anticoagulant PLA2s. A test of blood clotting revealed that E53G and W70M had lost their effects on the blood clotting, while T56K and D67K had enhanced activity. The four residues are located on the same face in the tertiary structure of this enzyme. The result supported the prediction that there exists an anticoagulant region that is composed of some residues that are close to each other in tertiary structure to form a functional face.
authors.affiliation: Institute of Biochemistry, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhong
authors.forename: Haomang
authors.initials: H
authors.lastname: Jiao
authors.forename: Liang
authors.initials: L
authors.lastname: Fan
authors.forename: Xiangfu
authors.initials: X
authors.lastname: Wu
authors.forename: Yuancong
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D017836:Agkistrodon; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D000925:Anticoagulants / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D016297:Mutagenesis, Site-Directed; D010741:Phospholipases A / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011517:Prothrombin Time; D013329:Structure-Activity Relationship; D014757:Viper Venoms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D000925:Anticoagulants; D014757:Viper Venoms; D010741:Phospholipases A