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. 1988 Mar;53(3):465–468. doi: 10.1016/S0006-3495(88)83124-2

A time-resolved spectral study of the K and KL intermediates of bacteriorhodopsin.

S J Milder 1, D S Kliger 1
PMCID: PMC1330215  PMID: 3349137

Abstract

Nanosecond time-resolved absorption measurements on the photolysis products of bacteriorhodopsin (BR) in intact membranes are reported. At room temperature in fluid solution a single intermediate (KL) is seen 10 ns after excitation. Both spectral and kinetic results are consistent with the KL intermediate converting to the L intermediate by a single first order reaction. The observed temperature-dependent rate has the Arrhenius parameters: Ea = 10.5 kcal/mol, A = 5 x 10(13) s-1. The precursor to the KL intermediate is also observed. Its spectral character is consistent with the K intermediate which has been previously reported. The current data is consistent with a linear sequence in the BR photocycle for K, KL, and L in room temperature fluid solution. Differences in the spectral characteristics of the K intermediates described here and elsewhere are discussed in terms of differences in the microenvironment around the retinal moiety and the affect this may have on the conformation of the chromophore.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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