Question

The enkephalins are naturally occurring compounds found in the central nervous system whose activity is imitated by morphine. The amino acid composition of one of the enkephalins is Gly-Gly-Met-Phe-Tyr. Reaction of this pentapeptide with 8-dimethylaminonapthalensulfonylchloride (dansyl chloride) and subsequent acid catalyzed hydrolysis affords the dansyl derivative of tyrosine as the only modified amino acid. When the enkephalin is treated with cyanogen bromide, no cleavage occurs. Partial hydrolysis of the pentapeptide with chymotrypsin gives only tyrosine, methionine and a tripeptide. a) What is the sequence of the enkephalin? b) What does the dansyl derivative of the tyrosine look like?

Answer 1