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Categorizing reactivity of bacteriorhodopsin cysteine mutants crosslinking to 4‐bromoretinal
Author(s) -
DattaGupta N.,
Crouch Rosalie K.,
Hazard E. Starr
Publication year - 1999
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549900201863
Subject(s) - bacteriorhodopsin , mutant , reactivity (psychology) , mutagenesis , chemistry , cysteine , chirality (physics) , molecular dynamics , stereochemistry , computational chemistry , biochemistry , physics , membrane , enzyme , medicine , chiral symmetry breaking , alternative medicine , pathology , quantum mechanics , nambu–jona lasinio model , gene , quark
The structure of bacteriorhodopsin (bR) has been probed by a large number of experimental methods. In earlier work distance constraints measured from the 1BRD Brookhaven structure (1, 2) were used to guide site‐directed mutagenesis/affinity labeling experiments (3‐5). In the present study we report on the use of limited molecular dynamics (MD) investigations of the same bR/affinity label system. We show here that the chiral center introduced when 4‐bromo‐all‐trans retinal is synthesized produces variable impact on potential crosslinking. Our MD analysis suggests the following ranking of binding site mutants in order of reactivity: R118C>S118C>> S121C>R141C>>S141C⋙R121C, R138C, S 138C. Chirality appears to have limited effect for the M118C mutants but shows more dramatic impact for the T121C and S141C mutants. These results are in excellent agreement with the experimental observations and offer encouragement that MD can be a useful component of experimental design with considerable predictive power.