Triton X-100对细菌视紫红质中间产物M_(412)的效应

本文研究用非离子表面活性剂Triton X-100处理后的细菌视紫红质(BR Bacteriorhodo-psin)光循环中间产物M_(412)动力学过程的变化.实验结果表明,用不同浓度的Triton处理pH=6.5的BR体系时,其中间产物M_(412).快衰减成分的半衰期(τ_(1/2)~f)在Triton浓度为0.05%(w/w)附近突然变慢,随着Triton浓度的加大,τ_(1/2)~f又逐渐加快;慢衰减部分的半衰期(τ_(1/2)~s)则随Tri-ton浓度的增加逐渐变慢.BR的生色团峰发生蓝移.说明不同浓度的Triton在水溶液中聚集状态不同,可不同程度地破坏膜脂的液晶态结构,从而导致镶嵌在其中的BR发生构象的变化,使转运质子的氢键通道受到不同程度的影响,故质子泵转运通道发生改变、致使M_(412)的衰减速率改变.

EFFECT OF NONIONIC DETERGENT TRITON X-100 ON INTERMEDIATE M412 OF BR PHOTOCYCLE

Changes in kinetic process of BR photocycle intermediate M412 of PM treated by nonionic detergent Triton X-100 were studied, with various concentrations of Triton X-100 in PH = 6.5 system, the half time of M412 fast decaying component (t1/2f) became slow abruptly around 0.05%(w/w) Triton concentration, then turned fast when increasing the concentration of Tritons while the half time of M412 slow decaying component (t1/2s) became slow gradually by raising Triton X-100 concentration. There were red shift of peak 275 and blue shift peak 568 in the PM treated with different concentrations of Triton. We suggest that the different assemble states of Triton moleclues in aqueous solution cause the damage of the intergrated liquid crystal texture of bilayer lipid to various degrees, then lead to the change of protein conformation and the channel of proton transition. The hydrogen bond networks used to transport proton are also influenced to various degrees. As a result, decay of M412 changes.