Purification, crystallization and preliminary X-ray diffraction analysis of saxthrombin, a thrombin-like enzyme from Gloydius saxatilis venom.
The snake-venom thrombin-like enzymes (SVTLEs) are a class of serine proteinases that show fibrinogen-clotting and esterolytic activities. Most TLEs convert fibrinogen to fibrin by releasing either fibrinopeptide A or fibrinopeptide B and cannot activate factor XIII. The enzymes hydrolyze fibrinogen to produce non-cross-linked fibrins, which are susceptible to the lytic action of plasmin. Because of these physiological properties, TLEs have important medical applications in myocardial infarction, ischaemic stroke and thrombotic diseases. Here, a three-step chromatography procedure was used to purify saxthrombin (AAP20638) from Gloydius saxatilis venom to homogeneity. Its molecular weight is about 30 kDa as estimated by SDS-PAGE. A saxthrombin crystal was obtained using the hanging-drop vapour-diffusion method and diffracted to a resolution limit of 1.43 A. The crystal belongs to space group C2, with unit-cell parameters a = 97.23, b = 52.21, c = 50.10 A, beta = 96.72 degrees , and the Matthews coefficient (V(M)) was calculated to be 2.13 A(3) Da(-1) with one molecule in the asymmetric unit.
Wei
Wenqing
W
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.
Zhao
Wei
W
Wang
Xiaoping
X
Teng
Maikun
M
Niu
Liwen
L
D000818:Animals; D003460:Crystallization; D008969:Molecular Sequence Data; D012910:Snake Venoms / Q000737:chemistry* / Q000302:isolation & purification; D013917:Thrombin / Q000737:chemistry* / Q000302:isolation & purification; D014961:X-Ray Diffraction
D012910:Snake Venoms; D013917:Thrombin