Bourne Y, Rougé P, Cambillau C
Groupe de Cristallographie des Proteines, CRMC-CNRS, Marseille, France.
J Mol Biol. 1988 Aug 5;202(3):685-7. doi: 10.1016/0022-2836(88)90299-9.
Two isolectins from the seeds of Lathyrus ochrus, LOL I and LOL II, which specifically bind N-acetyllactosamine, have been crystallized using the hanging-drop method and the interface diffusion method, respectively. In the case of LOL I, 2-methylpentane-2,4-diol, polyethylene-glycol 400 or ammonium sulphate have been used as precipitating agents. The best crystals of LOL I were grown at room temperature from a solution of 40% (v/v) methylpentane diol, 50 mM-Hepes at pH 7.5. LOL II crystals have been grown at room temperature from a solution of 32% (v/v) methylpentane diol, 50 mM-2-(N-morpholino)-ethanesulphonic acid at pH 5.5. X-ray examination of the LOL I and LOL II crystals shows that both are monoclinic, space group P2(1). Their cell dimensions are: LOL I, a = 56.4 A, b = 138.8 A, c = 62.9 A, beta = 91 degrees; and LOL II, a = 54.8 A, b = 71.4 A, c = 105.5 A, beta = 105 degrees. Density measurements of the crystals of LOL I indicate that there are two molecules per asymetric unit (Vm = 2.07 A3/dalton). LOL I crystals diffract strongly up to at least 1.8 resolution. Putative crystals of complexes of LOL I with various glycosides were obtained through co-crystallization under the conditions used for the native protein.
从山黧豆种子中提取的两种同工凝集素LOL I和LOL II，它们能特异性结合N-乙酰乳糖胺，分别采用悬滴法和界面扩散法进行了结晶。对于LOL I，使用了2-甲基戊烷-2,4-二醇、聚乙二醇400或硫酸铵作为沉淀剂。LOL I的最佳晶体是在室温下从40%（v/v）甲基戊烷二醇、pH 7.5的50 mM-HEPES溶液中生长得到的。LOL II晶体是在室温下从32%（v/v）甲基戊烷二醇、pH 5.5的50 mM-2-（N-吗啉代）乙磺酸溶液中生长得到的。对LOL I和LOL II晶体的X射线检查表明，两者均为单斜晶系，空间群为P2(1)。它们的晶胞参数为：LOL I，a = 56.4 Å，b = 138.8 Å，c = 62.9 Å，β = 91°；LOL II，a = 54.8 Å，b = 71.4 Å，c = 105.5 Å，β = 105°。LOL I晶体的密度测量表明，每个不对称单元中有两个分子（Vm = 2.07 Å3/道尔顿）。LOL I晶体在至少1.8 Å分辨率下仍能强烈衍射。通过在天然蛋白质所用条件下进行共结晶，获得了LOL I与各种糖苷的假定复合物晶体。
