Question

Examination of the amino acid composition of a newly isolated protein indicates the presence of 10 lysines, 5 arginines, and 3 methionines. When the protein is treated with cyanogen bromide, four peptides are obtained. When it is treated with trypsin, 15 peptides are obtained. What do these results suggest regarding the sequence of the protein?

Answer 1

Answer:

It means that the cyanogen bromide hydrolyzes methionine residues with high efficiency, while trypsin is an enzyme that cuts proteins at lysine and arginine peptidic bonds, thereby producing 4 and 15 polypeptides, respectively.

Explanation:

Cyanogen bromide is a pseudohalogen compound that is used to cut the C-terminus of the methionine residues. On the other hand, the trypsin is an enzyme produced by the pancreas as trypsinogen that is used by the digestive system (intestine) to digest polypeptides.