Question

biochemistry please show your work

2. A mutant form of polypeptide hormone angiotensin II has the amino acid composition: Ile, Arg, Met, Leu, Phe, Asp, Tyr, and Val. The following observations are made: 1) Treatment with trypsin yields a dipeptide containing Asp and Arg, and a hexapeptide with all the rest. 2) Cyanogen bromide yields a dipeptide containing Phe and Leu and a hexapeptide containing all the rest. 3) Chymotrypsin cleaves the hormone into two tetrapeptides of composition: Val, Tyr, Arg, Asp; and, Met, Leu, Phe, Ile. 4) The first product of Carboxypeptidase A cleavage is Phe. Trypsin creaves carboxyl sice O usor Arsex cl PŁ When Pro What is the sequence of the peptide? Show your reasoning. follows. can cleave at carboxyl 1. Ill, Arg, Met, Leu, Phe, ASP, Tyr, val CNBr side of met chymotrypsin cant creave after pro

Answer 1

1) treatment with carboxypeptidase A yield 1st amino acid phe from C terminus

2)treatment with lysin yield

N- asp-arg-x3-x4-x5-x6-x7-phe-c

3) cynogen bromide cut at methionine c-terminus cause release of one dipeptide phe-leu and a hexa peptide

So using this information x7 will be leu and x6 will be met

4) treatment with chymotrypsin cause cleaved at c terminus of aromatic releaseamino acid of two tetra peptide sequence, first made up of val,tyr,arg,asp so using this information it's right sequence will be

N- asp-arg- val-tyr-C

While other tetra peptide sequence is made up of met,leu,iso,phe so it's right sequence order will be N-ile- met-leu- phe-C

So final sequence will be

N- asp-arg-val-tyr-ile-met-leu-phe-C

Hope it's clear..thanks