Concomitant with the salting-out effect, according to which salts can be arranged in the Hofmeister series, there is a stabilizing effect, evidence for which has come primarily from observed increases in melting temperature T_m with salt concentration. Here we ask whether stabilization and destabilization can be manifested in ways more directly related to protein mechanism than the parameter T_m. For this purpose, we selected bac-teriorhodopsin (bR), whose operation can be followed through a richly detailed set of spectroscopic changes. Major coriformational changes accompany bR functional activity, especially during the later part of the photocycle (i.e. t > 1 ms). Hence photocycle kinetics should be affected if conformational destabilization occurs.
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