Sequence variability in the retinal-attachment domain of mammalian rhodopsins.

摘要: Ovine rhodopsin was regenerated with 11-cis-[15-3H]retinal and cleaved in situ by Staphylococcus aureus V8 proteinase to give two membrane-bound fragments of Mr 27 000 (V8-L) 12 (V8-S). After purification the proteolysed complex affinity chromatography concanavalin A-Sepharose 4B, [3H]retinal covalently linked protein reduction borohydride. The purified [3H]-retinyl V8-S fragment CNBr trifluoroacetic acid, resulting peptides resolved gel filtration [3H]retinyl peptide sequenced. protocol developed for isolation sequencing this region ovine applied directly, reproducibly, bleached unregenerated porcine equine opsins. Comparisons primary structures reveals marked variation sequence immediately after lysine residue shown be attachment point aldehyde group chromophore. Mutable positions are localized regions previously predicted as adopting nonregular or distorted conformations hint at structural arrangements that may provide a better understanding spectral functional properties visual pigment.