title: Purification, N-terminal sequencing, partial characterization, crystallization and preliminary crystallographic analysis of two glycosylated serine proteinases from Agkistrodon acutus venom.
abstract: AaV-SP-I and AaV-SP-II, two glycosylated serine proteinases from Agkistrodon acutus venom with fibrinogenolysis and esterolysis activities, have been purified to homogeneity by three-step ion-exchange chromatography. Estimated by SDS-PAGE, the molecular weights of AaV-SP-I and AaV-SP-II are about 32 and 31 kDa under reducing conditions and 26 and 25 kDa under non-reducing conditions, respectively. The first 24 N-terminal amino-acid residues are the same in both sequences and display a high homology with those of several snake-venom serine proteinases. However, the proteins possess obviously distinct carbohydrate contents. Using the conventional hanging-drop vapour-diffusion method, single crystals of both enzymes were grown that were suitable for X-ray diffraction analysis. The crystals of AaV-SP-I and AaV-SP-II belong to space groups P2(1)2(1)2(1) and C2, respectively. In each case there is only one molecule in the asymmetric unit.
authors.affiliation: Key Laboratory of Structural Biology, Chinese Academy of Sciences, School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, People's Republic of China.
authors.forename: Zhongliang
authors.initials: Z
authors.lastname: Zhu
authors.forename: Ping
authors.initials: P
authors.lastname: Gong
authors.forename: Maikun
authors.initials: M
authors.lastname: Teng
authors.forename: Liwen
authors.initials: L
authors.lastname: Niu
mesh_terms: D017836:Agkistrodon / Q000378:metabolism*; D000595:Amino Acid Sequence; D000721:Ancrod / Q000737:chemistry* / Q000302:isolation & purification; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002852:Chromatography, Ion Exchange; D003460:Crystallization; D018360:Crystallography, X-Ray; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D008970:Molecular Weight; D014961:X-Ray Diffraction
chemical_list: D002241:Carbohydrates; C477760:AaV-SP-I, Agkistrodon; C477759:AaV-SP-II, Agkistrodon; D000721:Ancrod