| Abstract: | The in vivo incorporation of 2-3H]-myo-inositol into frog retinal rod outer segment membranes was examined. About 25% of the recovered radioactivity was found to be protein-associated. Following acid hydrolysis of this material and extraction with hexane, all the radioactivity remained in the aqueous phase, indicating that the label was not in fatty acids. Following ion exchange column chromatography of the hydrolysate, the major radioactive compound comigrated on TLC with an internal standard of U-14C]-myo-inositol. SDS polyacrylamide gel electrophoresis of unextracted membranes indicated that the majority of the label was associated with opsin. These results indicate that 2-3H]-myo-inositol was incorporated in vivo into opsin, presumably with retention of its chemical identity. |
