a Synaptic vesicles (40 μg) were incubated for 6 min with 0.5 mM [32P]AMP in the absence or presence of 1 mM PEP, and the reaction mixture double-filtered and aliquots (0.1 ml) analyzed for products by HPLC, as described in Materials and Methods. Data indicate values calculated to represent the amount of ADP and ATP formed in the total incubation volume (0.3 ml), with mean ± SEM of three vesicle preparations. − PEP vs. + PEP: * p < 0.05. b
32P in [32P]AMP-derived [32P]ATP resides in the ADP moiety. Reaction products generated after incubation of synaptic vesicles (40 μg) for 30 min with 0.1 mM [32P]AMP (64 mCi/mmol) and 0.3 mM PEP were treated with hexokinase (0. 1 unit) in the presence of glucose (10 mM), and aliquots (0.05 ml) analyzed for [32P]ADP and [32P]ATP, as described in Materials and Methods. Data indicate values calculated to represent the amount of ADP and ATP found after hexokinase treatment in the total incubation volume (0.2 ml).