一种大豆种子脂氧合酶的结晶及初步X射线表征

Crystallization and preliminary X-ray characterization of a soybean seed lipoxygenase.

作者信息

Stallings W C, Kroa B A, Carroll R T, Metzger A L, Funk M O

机构信息

Physical Sciences Center, Monsanto Company, St Louis, MO 63198.

出版信息

J Mol Biol. 1990 Feb 20;211(4):685-7. doi: 10.1016/0022-2836(90)90067-V.

DOI:10.1016/0022-2836(90)90067-V

PMID:2313694

Abstract

An isoenzyme of soybean (Glycine max L. Merrill cv. Provar) lipoxygenase (EC 1.13.11.12) has been crystallized using the vapor diffusion method. Crystals were grown from solutions of the protein (7 mg/ml) using 10 to 20% (w/v) polyethylene glycol 8000 in citrate/phosphate buffer (pH 5.7) containing 0.5% (w/v) n-octyl-beta-D-glucopyranoside. The crystals reached maximum dimensions of 0.3 mm x 0.2 mm x greater than 2 mm. The enzyme crystallized in space group C222(1) with unit cell dimensions a = 246 A, b = 193 A and c = 75 A. A calculated Vm value of 2.35 A3/dalton was obtained assuming two molecules per asymmetric unit. The density of the crystals was found to be 1.16 g/ml, which confirmed the presence of two molecules per asymmetric unit and indicated a solvent content of 47.5%.

摘要

大豆（Glycine max L. Merrill cv. Provar）脂氧合酶（EC 1.13.11.12）的一种同工酶已通过气相扩散法结晶。晶体是从蛋白质溶液（7 mg/ml）中生长出来的，该溶液使用10%至20%（w/v）的聚乙二醇8000，置于含有0.5%（w/v）正辛基-β-D-吡喃葡萄糖苷的柠檬酸盐/磷酸盐缓冲液（pH 5.7）中。晶体的最大尺寸达到0.3 mm×0.2 mm×大于2 mm。该酶在空间群C222(1)中结晶，晶胞尺寸a = 246 Å，b = 193 Å，c = 75 Å。假设每个不对称单位有两个分子，计算得到的Vm值为2.35 Å³/道尔顿。发现晶体的密度为1.16 g/ml，这证实了每个不对称单位存在两个分子，并表明溶剂含量为47.5%。