Aldolase-catalyzed diketone phosphate formation from oxoaldehydes. NMR studies and metabolic significance.
NMR spectroscopy showed fructose-1,6-bisphosphate aldolase from rabbit muscle accepts as substrates, in lieu of glyceraldehyde 3-phosphate, the oxoaldehydes methylglyoxal and phenylglyoxal but not hydroxymethylglyoxal. The enzyme catalyzed an aldol condensation between the oxoaldehyde and dihydroxyacetone phosphate to form a monophosphorylated diketone and was inactivated in the process. Circumvention of this reaction, by metabolism of oxoaldehydes to hydroxy acids, may be a metabolic role for the glyoxalase enzyme system. Transketolase and transaldolase were found not to accept oxoaldehydes as substrates in place of glyceraldehyde 3-phosphate.
Rae
C
C
Department of Biochemistry, University of Sydney, New South Wales, Australia.
Bubb
W A
WA
Kuchel
P W
PW
D000818:Animals; D004099:Dihydroxyacetone Phosphate / Q000378:metabolism*; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism*; D006037:Glyoxal / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009132:Muscles / Q000201:enzymology; D010658:Phenylglyoxal / Q000378:metabolism; D011765:Pyruvaldehyde / Q000378:metabolism; D011817:Rabbits; D013379:Substrate Specificity
D006037:Glyoxal; D004099:Dihydroxyacetone Phosphate; D011765:Pyruvaldehyde; D005634:Fructose-Bisphosphate Aldolase; D010658:Phenylglyoxal