Chapter 9, Problem 1P

Interpretation Introduction

Interpretation: An explanation regarding the cleavage of the given amide substrate A by chymotrypsin reveals no burst by using stopped-flow kinetic methods is to be stated.

Concept introduction: The organic compounds that contain amine $\left({\text{-NH}}_{\text{2}}\right)$ and carboxyl $\left(\text{-COOH}\right)$ functional groups with a side chain $\left(\text{-R}\right)$ are known as amino acids. Amino acids consist of both positive as well negative groups in their structure and are called as ampholytes. The small chain of amino acids that is connected with the help of the amide bonds is known as peptide. A peptide possesses the covalent bonds which are formed by the reaction of carboxyl group of one amino acid with the amino group of other amino acids.

Proteolytic enzymes commonly known as proteases are used for the cleavage of protein. Chymotrypsin is an enzyme that is used for the cleavage of protein through hydrolysis reaction.

Answer to Problem 1P

The cleavage of the given amide substrate, A, by chymotrypsin reveals no burst because the acyl-enzyme intermediate formation occurs at a slower rate as compared to the hydrolysis for the given amide substrate.

Explanation of Solution

Given:

  

Chymotrypsin is an enzyme that is used for the cleavage of protein through hydrolysis reaction. In case of large hydrophobic amino acids, the cleavage of the peptide bond occurs particularly at the carboxyl-terminal side. In the given amide substrate A, the cleavage by chymotrypsin shows no burst because the hydrolysis for this substrate of amide is faster than the generation of the acyl-enzyme intermediate. In other words, the acyl-enzyme intermediate formation occurs at a slower rate as compared to the hydrolysis for the given amide substrate. Hence, no burst is found. In case of ester substrates, the acyl-enzyme intermediate formation occurs at a faster rate.