Biophysical Journal 44: 249-254 (1983)
© 1983 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Tsuda, M Articles by Ebrey, T G Search for Related Content PubMed PubMed Citation Articles by Tsuda, M Articles by Ebrey, T G

Effects of pressure and temperature on the M412 intermediate of the bacteriorhodopsin photocycle. Implications for the phase transition of the purple membrane.

ABSTRACT

The effects of pressure and temperature on the decay kinetics of the M412 (M) intermediate in the photocycle of bacteriorhodopsin were studied to provide information about the phase transitions of the purple membrane lipids. The activation volume (delta V++) for the decay of M is expected to be different below and above a phase transition. However, no abrupt change in delta V++ was found from 3.5 degrees to 60 degrees C. But a sharp break was observed in a plot of the logarithm of the rate of M decay vs. pressure. Extrapolation of this break point to standard atmospheric pressure gives a temperature of -42 degrees C, which probably corresponds to the phase transition of the purple membrane lipids. This conclusion is supported by studies of the effect of pressure on the M kinetics of bacteriorhodopsin incorporated into dimyristoylphosphatidylcholine vesicles, whose phase transition has previously been characterized.

This article has been cited by other articles:

				B. U. Klink, R. Winter, M. Engelhard, and I. Chizhov Pressure Dependence of the Photocycle Kinetics of Bacteriorhodopsin Biophys. J., December 1, 2002; 83(6): 3490 - 3498. [Abstract] [Full Text] [PDF]