Histidine Ammonia Lyase Mechanism

The video tutorial explores the catabolism of histidine, focusing on the unique mechanism catalyzed by histidine ammonia lyase. It highlights the role of the coenzyme methyl Ladin Imidazol, detailing the mechanistic steps including ligation, deprotonation, and beta elimination. The process involves the formation of an alkene and the regeneration of the cofactor, emphasizing the enzyme's role as a biological catalyst. The tutorial concludes with a recap and a discussion on the E1 mechanism involved.

What is the role of histidine ammonia-lyase in histidine catabolism?

• It catalyzes the synthesis of histidine.

• It catalyzes the committed step in histidine catabolism.

• It inhibits the catabolism of histidine.

• It acts as a cofactor in histidine synthesis.

What is the first mechanistic step in the catabolism of histidine?

• Ligation of the imidazole ring to the cofactor.

• Release of ammonia.

• Formation of a Schiff base.

• Deprotonation of the alpha carbon.

During the mechanism, what happens after the beta carbon is deprotonated?

• Formation of a carbonyl group.

• Release of urocanate.

• Double bond rearrangement.

• Formation of a Schiff base.

What type of elimination process is involved in the deamination of histidine?

• Delta elimination

• Alpha elimination

• Beta elimination

• Gamma elimination

What is the final product released from the enzyme after the mechanism?

• Histidine

• Ammonia

• Urocanate

• Methyl Ladin Imidazol

How is the elimination process in the mechanism classified?

• E2

• SN2

• SN1

• E1

What is regenerated at the end of the histidine catabolism mechanism?

• Urocanate

• Methyl Ladin Imidazol cofactor

• Ammonia

• Histidine