The effect of arabinose 1,5-bisphosphate on rat hepatic 6-phosphofructo-1-kinase and fructose-1,6-bisphosphatase.
The alpha- and beta-anomers of arabinose 1,5-bisphosphate and ribose 1,5-bisphosphate were tested as effectors of rat liver 6-phosphofructo-1-kinase and fructose-1,6-bisphosphatase. Both anomers of arabinose 1,5-bisphosphate activated the kinase and inhibited the bisphosphatase. The alpha-anomer was the more effective kinase activator while the beta-anomer was the more potent inhibitor of the bisphosphatase. Inhibition of the bisphosphatase by both anomers was competitive, and both potentiated allosteric inhibition by AMP. beta-Arabinose 1,5-bisphosphate was also more effective in decreasing fructose 2,6-bisphosphate binding to the enzyme. Neither anomer of ribose 1,5-bisphosphate affected 6-phosphofructo-1-kinase or fructose-1,6-bisphosphatase, indicating that the configuration of the C-2 (C-3 in Fru 2,6-P2) hydroxyl group is important for biological activity. These results are also consistent with arabinose 1,5-bisphosphate binding to the active site and thereby enhancing the interaction of AMP with the allosteric site.
D000249:Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D006597:Fructose-Bisphosphatase / Q000378:metabolism*; D005635:Fructosediphosphates / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D010428:Pentosephosphates / Q000494:pharmacology*; D010732:Phosphofructokinase-1 / Q000378:metabolism*; D051381:Rats; D013237:Stereoisomerism; D013696:Temperature
D005635:Fructosediphosphates; D010428:Pentosephosphates; D000249:Adenosine Monophosphate; C027652:fructose 2,6-diphosphate; C049747:arabinose 1,5-diphosphate; D010732:Phosphofructokinase-1; D006597:Fructose-Bisphosphatase