The interconversion of dihydroxyacetone phosphate and glyceraldehyde 3-phosphate catalyzed by the enzyme triosephosphate isomerase was first demonstrated by Meyerhof and Kiessling (1). Since then studies with the enzyme have disclosed little about the mechanism of this reaction. Such an interconversion may be envisioned as occurring by formation of an enediol as, based on chemical analogy (2)) ...

Aerobacter aerogenes strain 1033 can utilize glycerol as sole source of carbon and energy under aerobic and anaerobic conditions (2). With the aid of isotope enantiomorphs of glycerol1-V it could be shown that an important pathway of glycerol metabolism in this organism involves dihydroxyacetone as an intermediate between glycerol and pyruvate (3). The validity of this conclusion was strengthen...

High concentrations of orthophosphate (Pi) inhibited CO(2)-dependent O(2) evolution and prevented the inactivation of glucose-6-P dehydrogenase by light in intact spinach and barley chloroplasts. Addition of glycerate-3-P to chloroplasts inhibited by Pi in the light, induced O(2) evolution and caused rapid inactivation of glucose-6-P dehydrogenase. The activity of phosphofructokinase detected i...

The transaldolase-dihydroxyacetone carbanion intermediate formed in the reaction of transaldolase with its donor substrates fructose-6-P or sedoheptulose-7-P is susceptible to oxidation by hexacyanoferrate(III). The dihydroxyacetone moiety is oxidized to the corresponding 2-ketoaldehyde, i.e. hydroxy-pyruvaldehyde (CH2OH-CO-CHO). This oxidation product is, in contrast to dihydroxyacetone, readi...

A lipid, stable to alkaline methanolysis, is formed when liver mitochondria or brain microsomes are incubated with dihydroxyacetone phosphate, long chain alcohol, ATP, CoA, NaF and Mg*. The lipid has been identified as alkyl dihydroxyacetone phosphate. This lipid is reduced by NADPH to 1-alkyl glycerol3-phosphate and is further acylated to form 1-alkyl 2-acyl glycerol-3-phosphate. The ether-con...

The materials and general analytical methods have been described in some detail in a preceding communication (1). The assay method for a-glyeerophosphate dehydrogenase was essentially the same as that of Lowry and Passonneau (2). Since this enzyme catalyzes NADH-coupled reaction with dihydroxyacetone phosphate as substrate, one of the products, NAD2, may be measured with a sonsitive fluorometer...

The observation that molecules substituted with different isotopes may react at different rates has been of great value to the study of chemical reaction mechanisms. The theory and applications of this effect, particularly with isotopes of hydrogen, are well described in the literature (l-3), and frequent use is made of isotope effects in the study of the mechanism of enzyme reactions (4-6). On...