Nakamura M, Fujiwara A, Yasumasu I, Okinaga S, Arai K
J Biol Chem. 1982 Dec 10;257(23):13945-50.
Regulation of glucose metabolism in glycolysis by round spermatids was studied. Assay of activities of 11 glycolytic enzymes in cell-free spermatid extracts showed that hexokinase, phosphofructokinase, and glyceraldehyde-3-phosphate dehydrogenase had the lowest activities. When the cells were incubated with glucose (10 mM), the intracellular level of ATP fell rapidly and 5'-AMP increased. The ADP level remained unchanged. During incubation with glucose, fructose-1,6-bisphosphate, dihydroxyacetone phosphate, and glyceraldehyde-3-phosphate were accumulated without any change in a mass action ratio of fructose bisphosphate aldolase. Glyceraldehyde-3-phosphate dehydrogenase appeared to play a regulatory role in glycolysis. Glyceraldehyde-3-phosphate dehydrogenase was inhibited by the following compounds (Ki values in parentheses): adenosine (4.34 mM), 5'-AMP (3.50 mM), ADP (2.35 mM), ATP (5.34 mM), and 3',5'-cAMP (0.60 mM). In each case, the inhibition was competitive with NAD (Km = 0.20 mM). The 2'-hydroxy group of the adenine-linked ribose moiety was essential for binding. The compounds adenine, 2'-deoxyadenosine, 2'-AMP, 3'-AMP, CTP, GTP, UTP, and NADP showed little inhibition. These findings suggest that regulation of glycolysis in round spermatids by glyceraldehyde-3-phosphate dehydrogenase is most likely and that glyceraldehyde-3-phosphate dehydrogenase is inhibited by the adenine nucleotides, particularly by 5'-AMP and ADP as inhibitors competitive with NAD.
研究了圆形精子细胞对糖酵解中葡萄糖代谢的调节作用。对无细胞精子细胞提取物中11种糖酵解酶的活性测定表明，己糖激酶、磷酸果糖激酶和甘油醛-3-磷酸脱氢酶的活性最低。当细胞与葡萄糖（10 mM）一起孵育时，细胞内ATP水平迅速下降，5'-AMP增加。ADP水平保持不变。在与葡萄糖孵育期间，果糖-1,6-二磷酸、磷酸二羟丙酮和甘油醛-3-磷酸积累，而果糖二磷酸醛缩酶的质量作用比没有任何变化。甘油醛-3-磷酸脱氢酶似乎在糖酵解中起调节作用。甘油醛-3-磷酸脱氢酶受到以下化合物的抑制（括号内为Ki值）：腺苷（4.34 mM）、5'-AMP（3.50 mM）、ADP（2.35 mM）、ATP（5.34 mM）和3',5'-cAMP（0.60 mM）。在每种情况下，抑制作用均与NAD（Km = 0.20 mM）竞争。腺嘌呤连接的核糖部分的2'-羟基对于结合至关重要。腺嘌呤、2'-脱氧腺苷、2'-AMP、3'-AMP、CTP、GTP、UTP和NADP等化合物几乎没有抑制作用。这些发现表明，甘油醛-3-磷酸脱氢酶最有可能调节圆形精子细胞中的糖酵解，并且甘油醛-3-磷酸脱氢酶受到腺嘌呤核苷酸的抑制，特别是受到5'-AMP和ADP作为与NAD竞争的抑制剂的抑制。
