Question

Chymotrypsin is an enzyme that catalyzes the hydrolytic cleavage of the peptide bond after large hydrophobic residues.What is the function of the hydrophobic pocket? What amino acids would you expect to find in that pocket (the enzyme’s amino acid’s – not the amino acids of the protein being cleaved)? If a residue in the hydrophobic pocket was mutated to a Glu (and the protein did not change its tertiary structure), what would you expect to happen to the specificity of the enzyme?

Answer 1

Three questions in one answer

Step-by-step explanation:

The pocket works as a 'complementary center' in the sense that large hydrophobic residues of the protein to be cleaved can enter into it and fit, giving enough time for the chemotrypsin action center to break one of its peptide bonds. You will expect to find polar residues forming this pocket, otherwise, hydrophobic side chains of proteins to be cleaved will not enter the pocket. If we assume that one residue of the pocket is mutated for Glu without losing tertiary structure (which is unrealistic), the specificity of the enzyme will diminish dramatically. The efficacy of the action center depends on the ability of the pocket and a large hydrophobic residue to fit together and it is lost by the addition of an electrically charged residue as Glu.