Question

A sample of peptide of unknown sequence was treated with trypsin to produce the following smaller peptides:

1) Met-Val-Ser-Thr-Lys
2) Val-Ile-Trp-Thr-Leu-Met-Ile
3) Leu-Phe-Asn-Glu-Ser-Arg
Another sample of the same peptide was treated with chymotrypsin and gave the following smaller peptides:
1) Asn-Glu-Ser-Arg-Val-Ile-Trp
2) Thr-Leu-Met-Ile
3) Met-Val-Ser-Thr-Lys-Leu-Phe
What is the sequence of the original peptide?

Answer 1

The sequence is >> Met-Val-Ser-Thr-Lys-Leu-Phe-Asn-Glu-Ser-Arg-Val-Ile-Trp-Thr-Leu-Met-Ile, or abbreviated M-V-S-T-K-L-F-N-E-S-R-V-I-W-T-L-M-I

Explanation:

Trypsin is a serine protease enzyme capable of hydrolyzing different types of proteins. This enzyme is used in biotechnology and molecular biology to hydrolyze at the carboxyl side of arginine or lysine residues. Moreover, chymotrypsin is another digestive protease that also catalyzes the breakdown of proteins into small polypeptide chains. This enzyme cuts the C-terminal side of aromatic amino acids such as tryptophan (W), tyrosine (Y) and phenylalanine (F) on peptide chains.