Abstract
With the L. delbrueckii enzyme the reduction of flavin-adeninedinucleotide (FAD) by pyruvate depends on the presence of PO4; the H transfer is tightly coupled with phosphorylation of the oxidation product. These results are interpreted as an integrated reaction between TPP, pyruvate, and FAD, with the pyruvate not being oxidized if PO4 is not present to accept the active acetyl.