A peptide P with the amino acid composition (A,E,F,G₂,H,K,L,M,P,R,V,Y) did not yield to MS–MS sequencing, so it was hydrolyzed with trypsin to three peptides, T1, T2, and T3, which were found by MS–MS to have the following structures:

(The parentheses in T3 mean that the order of L and P could not be determined.) Hydrolysis of P catalyzed by chymotrypsin yielded three peptides, C1, C2, and C3, which were sequenced by MS–MS and found to have the following structures:

What is the amino acid sequence of peptide P?

Transcribed Image Text:

TI: A-H-K T2: E-M-V T3: (L,P)-F-G-G-Y-R