Question

Explain Triosephosphate Isomerase mechanism in the simplest way

Answer 1

Triosephosphate Isomerase (TPI) is an isomerase that catalyzes the isomerization of dihydroxyacetone phosphate to and from D-glyceraldehyde 3-phosphate.

This mechanism involves vry few steps.

It involves transfer of protons only.

It takes part in the glycolytic pathway, which is the biochemical pathway employed by many organisms.

The objective of this pathway is to metabolize glucose into two pyruvate molecules, also producing two ATP molecules.

TPI is an enzyme that contributes to the production of ATP, the molecules used as an energy source by all organisms.

TPI is an example of a "kinetically perfect enzyme," It catalyzes isomerization so quickly that the rate of reaction is determined by the diffusion rate of the substrate. This isomerizes essentially every molecule of TPI specificity that it encounters. TPI increases the rate of isomerization by ten degrees of magnitude. Part of TPI's kinetical perfection comes from it being an isomerase; the enzyme does not have to wait for multiple substrates to bind to the active site.