Gennis R B, Sinensky M, Strominger J L
J Biol Chem. 1976 Mar 10;251(5):1270-6.
Physicochemical techniques were used to investigate the activation of C55-isoprenoid alcohol phosphokinase by synthetic lecithins. Complexes of the enzyme with phospholipids were prepared using a method employing sodium dodecyl sulfate as a protein-solubilizing agent. Circular dichorism and the intrinsic fluorescence of the kinase were used as optical probes of protein conformation with these complexes. No evidence for a major lipid-dependent conformational change in the protein was observed when these complexes were studied under conditions where the lipid mesomorphic transitions occurred. EPR studies of mixtures of synthetic lecithins and the C55-isoprenoid alcohol indicated a correlation between kinase activity and the rotational diffusion rate within the hydrophobic phase. It is concluded that the lipid physical state probably does not affect the enzyme activity by altering the protein conformation but more likely does so by affecting the motion of the molecular participants in the reaction.
采用物理化学技术研究合成卵磷脂对C55 - 异戊二烯醇磷酸激酶的激活作用。使用十二烷基硫酸钠作为蛋白质增溶剂的方法制备酶与磷脂的复合物。圆二色性和激酶的固有荧光被用作这些复合物蛋白质构象的光学探针。当在脂质介晶转变发生的条件下研究这些复合物时，未观察到蛋白质中存在主要的脂质依赖性构象变化的证据。对合成卵磷脂和C55 - 异戊二烯醇混合物的电子顺磁共振研究表明，激酶活性与疏水相内的旋转扩散速率之间存在相关性。得出的结论是，脂质物理状态可能不会通过改变蛋白质构象来影响酶活性，而更有可能是通过影响反应中分子参与者的运动来实现的。
