Joshi M K, Dracheva S, Mukhopadhyay A K, Bose S, Hendler R W
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892-0510, USA.
Biochemistry. 1998 Oct 13;37(41):14463-70. doi: 10.1021/bi980965j.
Brief treatment of purple membrane (PM) with dilute detergent can cause major disruption of the BR photocycle without disrupting the trimer structure of BR [Mukhopadhyay et al. (1996) Biochemistry 35, 9245-9252]. Normal photocyle behavior can be recovered by incubating the damaged membranes with a total extract of the five types of native lipids present in PM. It is shown here that full restoration can also be obtained with combinations of squalene (SQ) and phosphatidyl glycerophosphate (PGP) which act synergistically. The addition of SQ to suboptimal levels of PGP induces complete reconstitution, principally by restoring the characteristics of the fast M intermediate, Mf (as defined in Mukhopadhyay et al. (1996) Biochemistry 35, 9245-9252). The addition of small amounts of PGP to SQ, which alone is ineffective, also induces full reconstituion. At very high levels, full reconstitution can be obtained with PGP alone. These results, in combination with earlier studies which implicate an acidic amino acid residue [Bose et al. (1997) J. Phys. Chem. B 101, 10584-10587], suggest that a crucial interaction between a particular amino acid residue and a SQ-PGP lipid complex may be essential for normal BR photocycle activity.
用稀洗涤剂对紫膜（PM）进行短暂处理会导致细菌视紫红质（BR）光循环的主要破坏，但不会破坏BR的三聚体结构[Mukhopadhyay等人（1996年），《生物化学》35卷，9245 - 9252页]。通过将受损膜与PM中存在的五种天然脂质的总提取物一起孵育，可以恢复正常的光循环行为。本文表明，角鲨烯（SQ）和磷脂酰甘油磷酸酯（PGP）的组合也能实现完全恢复，它们具有协同作用。将SQ添加到次优水平的PGP中可诱导完全重构，主要是通过恢复快速M中间体Mf的特性（如Mukhopadhyay等人（1996年）在《生物化学》35卷，9245 - 9252页中所定义）。向单独无效的SQ中添加少量PGP也能诱导完全重构。在非常高的水平下，单独使用PGP就能实现完全重构。这些结果与早期涉及酸性氨基酸残基的研究[Bose等人（1997年），《物理化学杂志B》101卷，10584 - 10587页]相结合，表明特定氨基酸残基与SQ - PGP脂质复合物之间的关键相互作用可能对正常的BR光循环活性至关重要。
