A hexapeptide has the composition `Ala,Gly,Phe,Val.` Both the `N-` terminal and `C-` teminal units are Val. Cleavage of the hexapeptide by chymotypsin gives two different tripeptides, both having Val as the N-terminal group. Among the products of random hydrolysis is a `Ala-Val` dipeptide fragment . What is the primary structure of the hexapeptide?

Answer

6

Explanation

By writing the possible structures of peptides by applying the given conditions we can count.