Wigley D B, Muirhead H, Gamblin S J, Holbrook J J
Department of Biochemistry University of Bristol Medical School, England.
J Mol Biol. 1988 Dec 20;204(4):1041-3. doi: 10.1016/0022-2836(88)90060-5.
Bacillus stearothermophilus lactate dehydrogenase was purified from an overexpressing Escherichia coli cell line. The enzyme has been crystallized in several different forms. All of these crystal forms were grown in the presence of NADH, sodium oxamate and fructose 1,6-bisphosphate. Three crystal forms have been characterized, an orthorhombic P2(1)2(1)2 (type III, a = 86 A, b = 105 A, c = 136 A) and two monoclinic P21 forms (type IV, a = 85 A, b = 118 A, c = 136 A, beta = 96 degrees; type V, a = 112 A, b = 85 A, c = 136 A, beta = 91 degrees). Precession photographs from these crystal forms are very alike, suggesting the molecular packing to be similar in all three forms. The P21 type IV crystals diffract to beyond 2 A spacing and are stable to irradiation with X-rays. A complete medium-resolution (4.7 A) dataset has been collected from a single crystal using synchrotron radiation. Rotation function studies with these data show the two tetramers of the asymmetric unit to be in very similar orientations. Higher-resolution data are being collected.
嗜热栖热芽孢杆菌乳酸脱氢酶是从一个过表达的大肠杆菌细胞系中纯化得到的。该酶已结晶为几种不同的形式。所有这些晶体形式都是在烟酰胺腺嘌呤二核苷酸（NADH）、草酸钠和1,6-二磷酸果糖存在的情况下生长的。已对三种晶体形式进行了表征，一种正交晶系P2(1)2(1)2（III型，a = 86 Å，b = 105 Å，c = 136 Å）和两种单斜晶系P21形式（IV型，a = 85 Å，b = 118 Å，c = 136 Å，β = 96°；V型，a = 112 Å，b = 85 Å，c = 136 Å，β = 91°）。这些晶体形式的进动照片非常相似，表明这三种形式的分子堆积相似。P21 IV型晶体的衍射分辨率超过2 Å间距，并且对X射线辐照稳定。使用同步辐射从单个晶体收集了完整的中分辨率（4.7 Å）数据集。对这些数据进行的旋转函数研究表明，不对称单元的两个四聚体具有非常相似的取向。更高分辨率的数据正在收集当中。
