Pyruvate-glyoxylate carboligase activity of the pyruvate dehydrogenase complex of Escherichia coli

Inactivation of the pyruvate dehydrogenase complex of Escherichia coli by fluoropyruvate

“…The apparently anomalous kinetics at high fluoropyruvate concentrations in Figure 1 and Table I can be explained by the carboligase activity of E! (Kubasik et al, 1972). In the carboligase reaction a molecule of pyruvate is decarboxylated to hydroxyethylidene-TPP at the E[ site, and this intermediate reacts with a second molecule of pyruvate to form acetolactate (see Discussion).…”

“…The analogy may be very close since, as discussed in the following section, the inactivation by fluoropyruvate is a suicide process touched off by the decarboxylase action of the enzyme. Pyruvate dehydrogenase, the Et component, is known to catalyze a carboligase activity at high concentrations of the substrate pyruvate to form C02 and acetolactate according to eq 3 (Kubasik et al, 1972). (3)…”

Thiamin-Diphosphate-Dependent Enzymes: New Aspects of Asymmetric CC Bond Formation

“…Another very interesting aim is chain elongation through transformation of a C‐1 unit (formaldehyde or equivalent), which is very difficult to perform selectively by nonenzymatic catalysis 37. Several ThDP‐dependent enzymes (TK,38 PDC,7, 39 dihydroxyacetone synthase (DHAS),40 and glyoxylate carboligase (GCL)41) are known to catalyze such reactions, although mostly in a nonasymmetric manner.…”

Formation of 1-Deoxy-ketoses by Pyruvate Dehydrogenase and Acetoin Dehydrogenase

“…4 ) However, 1-deoxy-ketose formation by PDH has not hitherto been reported. It has also been demonstrated that acetaldehyde, acetoin and diacetyl can serve as alternative substrates of PDH in the presence of an oxidant 3 ) and that diacetyl is an alternative substrate in the overall reaction of PDC.…”