Smith P F, Koostra W L, Mayberry W R
J Bacteriol. 1969 Dec;100(3):1166-74. doi: 10.1128/jb.100.3.1166-1174.1969.
The cytoplasmic membrane of Mycoplasma laidlawii strain B is solubilized by anionic and nonionic detergents, succinylation, phospholipase A, alkaline phosphatase, trypsin, and chymotrypsin. Cationic detergents are without effect, as are chelating agents, even in the presence of high concentrations of monovalent cation. The detergent-solubilized membrane exhibits one peak in the analytical ultracentrifuge, but the sedimentation coefficient is dependent upon concentration of detergent. Simple dialysis does not remove all of the sodium dodecylsulfate except from lipid-depleted membrane particles. Membranes bind sodium dodecylsulfate but acetone powders of membranes do not. Sulfated alcohols with chain lengths of C(14) and C(16) are more tightly bound than dodecylsulfate. A constant amount of di- and trivalent cation is bound by the membrane upon aggregation. Only a portion of this cation is removable with chelating agents. No chelating agent is bound by these aggregates. A portion of the lipid-depleted membrane particles is solubilized by negatively charged lipids and detergents, giving rise to aggregates in the presence of divalent cation. Fractionations of detergent-solubilized membranes by preparative gel electrophoresis and ammonium sulfate were inconclusive. Density gradient centrifugation of succinylated membranes yielded at least five fractions which exhibited homogeneity by ultracentrifugation. Analytical gel electrophoresis of these fractions demonstrated heterogeneity. The composition of these five fractions suggested separation of protein from lipid.
莱氏无胆甾原体B株的细胞质膜可被阴离子和非离子去污剂、琥珀酰化、磷脂酶A、碱性磷酸酶、胰蛋白酶和糜蛋白酶溶解。阳离子去污剂则无此作用，螯合剂也是如此，即使在高浓度单价阳离子存在的情况下。经去污剂溶解的膜在分析超速离心机中呈现一个峰，但沉降系数取决于去污剂的浓度。简单透析不能除尽所有的十二烷基硫酸钠，脂质耗尽的膜颗粒除外。膜能结合十二烷基硫酸钠，但膜的丙酮粉则不能。链长为C(14)和C(16)的硫酸化醇比十二烷基硫酸盐结合得更紧密。膜聚集时会结合一定量的二价和三价阳离子。这些阳离子中只有一部分能用螯合剂除去。这些聚集体不结合任何螯合剂。一部分脂质耗尽的膜颗粒可被带负电荷的脂质和去污剂溶解，在二价阳离子存在的情况下会形成聚集体。用制备性凝胶电泳和硫酸铵对经去污剂溶解的膜进行分级分离，结果并不明确。对琥珀酰化膜进行密度梯度离心，得到至少五个级分，经超速离心显示具有均一性。对这些级分进行分析性凝胶电泳显示存在异质性。这五个级分的组成表明蛋白质与脂质已分离。
