title: Location of lysine-129 and lysine-40/41 with respect to retinylidene chromophore in bacteriorhodopsin.
abstract: Fluorescence properties of fluorescamine-modified bacteriorhodopsin (BR) have been studied. BR reacts with fluorescamine (1:2 ratio) to give protein (FLBR-I) modified at Lys-129. By making use of citraconic anhydride as a masking reagent, fluorescamine modification of Lys-40/41 in BR has been achieved. Forster's resonance energy transfer studies indicate that the distance between FL-Lys-129 and retinylidene chromophore is 11 A, whereas that between FL-Lys-40/41 and retinylidene chromophore is 24 A. These measured distances have been analysed in terms of BR structure.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Powai, Bombay.
authors.forename: S M
authors.initials: SM
authors.lastname: Sonar
authors.forename: A K
authors.initials: AK
authors.lastname: Singh
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry*; D004735:Energy Transfer; D005450:Fluorescamine; D006217:Halobacterium / Q000378:metabolism; D008239:Lysine; D008961:Models, Structural; D011485:Protein Binding; D011487:Protein Conformation; D012176:Retinoids / Q000032:analysis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D014961:X-Ray Diffraction
chemical_list: D012176:Retinoids; D005450:Fluorescamine; D001436:Bacteriorhodopsins; D008239:Lysine