2. Amino acid analysis of an oligopeptide seven residues long gave: asp, leu, lys, met, phe and tyr. The following facts were observed: a. Trypsin treatment had no apparent effect. b. The phenylhydantoin released by Edman degradation was CH otto c. Brief chymotrypsin treatment yielded several products, including a dipeptide and a tetrapeptide. The amino acid composition of the tetrapeptide was leu, lys, and met. d. Cyanogen bromide treatment yielded a dipeptide, a tetrapeptide, and free lysine. What is the amino acid sequence of this heptapeptide?