THE MOLECULAR-MOTION OF BACTERIORHODOPSIN MUTANT D96N IN THE PURPLE MEMBRANE

We measured the flash-induced absorption anisotropies of mutant bacter iorhodopsin (bR), D96N, in the purple membrane suspension, The measure d anisotropy decay at 410 nm differed from that at 570 Mn. These wavel ength-dependent anisotropies show that the motion of absorption dipole of non-excited bR is faster than that of M-intermediate, The motion o f non-excited bR is considered as the rotational motion of whole prote in in the purple membrane, This fact suggests that the photo-excitatio n induces the conformational change of the protein and/or the inter-pr otein interaction within the membrane, which prevents the motion of M- intermediate.