Trypsin and elastase are both enzymes that catalyze hydrolysis of peptide bonds.However, trypsin only hydrolyzes peptide bonds next to lysine, and elastase only hydrolyzes peptide bonds next to alanine.Why?

Question

Quizplus · Accepted Answer

The shapes of the active sites for the two enzymes are different. The specificity of trypsin and elastase for lysine and alanine, respectively, is due to the shape and complementary nature of their respective active sites. Trypsin has a catalytic triad composed of Asp, His, and Ser residues and a deep, narrow pocket that accommodates the basic side chain of lysine. Elastase, on the other hand, has a smaller pocket with a hydrophobic surface that preferentially binds the small side chain of alanine.

Trypsin and Elastase Are Both Enzymes That Catalyze Hydrolysis of Peptide