Question

Summarize the mechanism of the mammalian serine protease. You

mustsupply both words and a sketch of the process. Remember to
mentionthe roles of the tetrahedral intermediates, the oxyanion
holes, andthe catalytic triad.

Answer 1

Answer and Explanation:

Summarily, the mammalian serine protease has an -OH group which is able to act as a nucleophile, thus attacking the carbonyl carbon of the scissile peptide bond of the substrate. Then a pair of electrons on the histidine nitrogen having the ability to accept the hydrogen from the serine -OH group, thus coordinating the attack of the peptide bond.

The tetrahedral intermediates formation is the rate determining step.

Oxyanion hole (black) stabilises negative charge build-up on the transition state of the substrate (red) using hydrogen bonds from the enzyme's backbone amides (blue).

The catalytic triad is the main player in the catalytic mechanism in the serine proteases and plays an essential role in the cleaving ability of the proteases.

The attachments below shows the sketch of the process.