The adenosine diphosphate--adenosine triposphate-excange reaction of cerebral microsomes and its relation to he sodium ion-stimulatd adenosine-triphosphatase reaction.
Microsomes from guinea-pig cerebral cortex contain a system capable of exchanging ADP with ATP at rates of about 20mumoles/mg. of protein/hr. The ADP-ATP-exchange reaction requires Mg(2+) for activity. The reaction is not stimulated by Na(+) or K(+) and is not inhibited by ouabain, in contrast with the Na(+)-plus-K(+)-stimulated adenosine triphosphatase. The pH optimum also differs from that of the adenosine triphosphatase. The ADP-ATP-exchange reaction is stimulated two- to three-fold by non-ionic, anionic and cationic detergents, even when these agents are inhibiting the adenosine-triphosphatase reaction. This reaction may represent a component of the Na(+)-plus-K(+)-stimulated adenosine-triphosphatase reaction but is more likely to be due to other enzyme systems present in microsomal subfractions.
D000227:Adenine Nucleotides / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002540:Cerebral Cortex / Q000166:cytology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008861:Microsomes / Q000201:enzymology* / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology*; D013385:Succinate Dehydrogenase; D013501:Surface-Active Agents / Q000494:pharmacology
D000227:Adenine Nucleotides; D013501:Surface-Active Agents; D010042:Ouabain; D000255:Adenosine Triphosphate; D012964:Sodium; D013385:Succinate Dehydrogenase; D000251:Adenosine Triphosphatases