Distortion of the L→M transition in the photocycle of the bacteriorhodopsin mutant D96N: a time-resolved step-scan FTIR investigation
| Autor: | C Rödig, F Siebert |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Time Factors
Mutant Biophysics Bacteriorhodopsin Model system Biochemistry Step-scan Fourier transform spectroscopy Structural Biology Spectroscopy Fourier Transform Infrared Genetics Fourier transform infrared spectroscopy Molecular Biology Aspartic Acid Transition (genetics) biology Chemistry Wild type Cell Biology D96N mutant Microsecond Crystallography Bacteriorhodopsins Mutagenesis Site-Directed biology.protein Time-resolved infrared spectroscopy Asparagine Wild type protein |
| Zdroj: | FEBS Letters. 445:14-18 |
| ISSN: | 0014-5793 |
| DOI: | 10.1016/s0014-5793(99)00088-5 |
| Popis: | The D96N mutant of bacteriorhodopsin has often been taken as a model system to study the M intermediate of the wild type photocycle due to the long life time of the corresponding intermediate of the mutant. Using time-resolved step-scan FTIR spectroscopy in combination with a sample changing wheel we investigated the photocycle of the mutant with microsecond time resolution. Already after several microseconds an intermediate similar to the MN state is observed, which contrasts with the M state of the wild type protein. At reduced hydration M and N intermediates similar to those of wild type BR can be detected. These results have a bearing on the interpretation of the photocycle of this mutant. A mechanism is suggested for the fast rise of MN which provides some insight into the molecular events involved in triggering the opening of the cytosolic channel also of the wild type protein. |
| Databáze: | OpenAIRE |
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