THE EFFECT OF REMOVAL OF THE CARBOXYL-TERMINAL PEPTIDE OF BACTERIORHODOPSIN ON ROTATION DIFFUSION OF BACTERIORHODOPSIN IN DMPC VESICLES
切割菌紫质分子C端多肽对脂质泡中菌紫质分子在膜中旋转运动的影响

The rotational diffusion of bacteriorhodopsin and papain-treated baeterior-hodopsin reconstituted into DMPC vesicles were measured by the technique of flash-induced transient dichroism. The results show that rotational diffusion of papain-treated bacteriorhodopsin is faster than rotational diffusion of bacterio-rhodopsin(T1 become shorter). The numbers of immobilized melecules of papain -treated bacteriorhodopsin is less than that of bacteriorhodopsin (r3% become smaller). In the presence of melittin and acetyl-melittin,dose-dependent loss of rotational mobility of bacteriorhodopsin and papain-treated bacteriorhodopsin was observed.The loss of rotational mobility of bacteriorhodopsin is larger than pa-pain-treated bacteriorhodopsin.This suggests that the charge of bacteriorhodopsin itself doesn't affect ro-tatinal diffusion of bacteriorhodopsin, tut when bacteriorhodopsin interacts with melittin or acetyl-melittin, the electrostatic attraction between them causes the aggregation of bacteriorhodopsin through melittin.In this case,charge of bacteriorhodopsin affects the rotational diffusion of bacteriorhodopsin.