PEPTIDE PATTERN STUDIES ON BOVINE RHODOPSIN

1. 1.|Rhodopsin was extracted from the rod outer segments of bovine retinae using 3% cetyltrimethylammonium bromide (CTAB) in 0.2 M sodium phosphate buffer (pH 7). Bovine opsin was then prepared by exclusion and ion-exchange chromatography of the bleached, CTAB-extracted rhodopsin. The protein homogeneity of the opsin was established by polyacrylamide-gel electrophoresis. 2. 2.|Reduced and carboxymethylated (RCM) opsin and RCM-retinylopsin were also purified in this manner. 3. 3.|Peptide patterns of trypsin and cyanogen bromide digests of bovine opsin, RCM-opsin and RCM-retinylopsin were obtained. The peptide patterns of the trypsin digests of RCM-opsin were examined for arginine, tryptophan, and histidine residues. In all cases the numbers of residues found were in good agreement with the predicted values. © 1969.