醛缩酶催化由氧代醛形成二酮磷酸酯。核磁共振研究及代谢意义。
Aldolase-catalyzed diketone phosphate formation from oxoaldehydes. NMR studies and metabolic significance.
作者信息
Rae C, Bubb W A, Kuchel P W
机构信息
Department of Biochemistry, University of Sydney, New South Wales, Australia.
出版信息
J Biol Chem. 1992 May 15;267(14):9713-7.
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.
核磁共振光谱显示，兔肌肉中的果糖-1,6-二磷酸醛缩酶可接受氧代醛甲基乙二醛和苯乙二醛作为底物来替代3-磷酸甘油醛，但不接受羟甲基乙二醛。该酶催化氧代醛与磷酸二羟丙酮之间的醛醇缩合反应，形成单磷酸化二酮，并在此过程中失活。通过将氧代醛代谢为羟基酸来规避此反应，可能是乙二醛酶系统的一种代谢作用。发现转酮醇酶和转醛醇酶不能接受氧代醛作为底物来替代3-磷酸甘油醛。
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