A strong band at 412 nm has been observed in the photoacoustic spectrum of partially dried purple membrane, peaking sharply at a modulation frequency of about 70 Hz. This may be explained in terms of a disorder-order transition. bR, bacteriorhodopsin; bR(570), M(412), M'(390), N(530), intermediates in the bacteriorhodopsin photocycle; PA, photoacoustic; PAS, photoacoustic spectroscopy.
Photoacoustic spectroscopy of purple membrane fragments evidence for disorder during photocycle. Publishing Authors By Initials