Formation of adenosine 5'-phosphorofluoridate and the assay of adenyl cyclase in barley seeds

Barley seed (Hordeum vulgare L.) homogenates contain an apparent enzymatic activity which catalyzes the synthesis of adenosine 5′-phosphorofluoridate from magnesium-adenosine 5′-triphosphate and sodium fluoride. Formation of this compound may interfere with some adenyl cyclase assays which use fluoride as a component of the incubation medium. Neither adenyl cyclase activity nor endogenous adenosine 3′: 5′-monophosphate was detected in barley seed homogenates or extracts.