[3] Pyruvate decarboxylase depends on cofactors thiamine pyrophosphate (TPP) and magnesium.

A mutation at the active site involving these Glu can result in the inefficiency or inactivity of the enzyme.

Two Cys-221 (more than 20 Ångstroms away from each site) and His-92 trigger a conformational change, which inhibits or activates the enzyme depending on the substrate availability.

The CH center located between the sulfur and nitrogen atoms on thiazole ring is acidic.

[3] During the decarboxylation of pyruvate, the TPP stabilizes the carbanion intermediates as an electrophile by noncovalent bonds.

[4] Specifically, the pyridyl nitrogen N1' and the 4'-amino group of TPP are essential for the catalytic function of the enzyme-TPP complex.

The intermediate loses carbon dioxide, giving an enol, in an irreversible step.

[7] In yeast, pyruvate decarboxylase acts independently during anaerobic fermentation and releases the 2-carbon fragment as acetaldehyde plus carbon dioxide.

[4] The enzyme is necessary to help the decarboxylation of alpha-keto acids because there is a build-up of negative charge that occurs on the carbonyl carbon atom in the transition state; therefore, the enzyme provides the suitable environment for TPP and the alpha-keto acid (pyruvate) to meet.