Regulation of glucose metabolism by adenine nucleotides in round spermatids from rat testes.
M Nakamura, A Fujiwara, I Yasumasu, S Okinaga, K Arai
Index: J. Biol. Chem. 257 , 13945-13950, (1982)
Full Text: HTML
Abstract
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.
Related Compounds
Related Articles:
Anaerobic growth of Bacillus mojavensis and Bacillus subtilis requires deoxyribonucleosides or DNA.
2004-09-01
[Appl. Environ. Microbiol. 70 , 5252-7, (2004)]
Detection and visualization of protein interactions with protein fragment complementation assays.
2002-01-01
[Methods Mol. Biol. 185 , 447-59, (2002)]
2007-12-01
[Biol. Reprod. 77 , 960-969, (2007)]
1993-01-01
[Int. J. Fertil. 38 , 123-128, (1993)]
Uptake and utilization of nucleosides for energy repletion.
2005-04-01
[Int. J. Biochem. Cell Biol. 37 , 797-808, (2005)]