Question

Arrange the events for the hydrolysis of amide bonds by chymotrypsin in their correct order. 1) attack by ser 195 to give a tetrahedral intermediate 2) enzyme returns to initial state 3) protonation by his 57 and then cleavage of the c-n bond release the c-terminal fragment 4) protonation by his 57 and then cleavage of the c-o bond release the n-terminal fragment 5) attack by water, leading to formation of a tetrahedral intermediate 6) binding of substrate to properly position the scissile bond for cleavage

Answer 1

The correct order is : 6,1,3,5,4,2.

Explanation:

Events of Hydrolysis of amide bonds by chymotrypsin is as follows:

Firstly, 6, Binding of Substrate to properly position the scissile bond for cleavage.

Then, 1, attack by ser 195 to give a tetrahedral intermediate

3, protonation by his 57 and then cleavage of the c-n bond releases the c-terminal fragment

5, attack by water, leading to formation of a tetrahedral intermediate

4, protonation by his 57 and then cleavage of the c-o bond releases the n-terminal fragment

2, enzyme returns to initial state