... Nitrocellulose membranes were exposed to film, and each spot was cut out and counted by liquid scintillation.ATP hydrolysis and TLCATP hydrolysis was determined by measuring the release of[32P]phosphate ... 8-azido-[32P]ATP[aP] werevisualized by autoradiography of dried gels. Specificityof binding to IRP-1 was demonstrated by competitionwith unlabeled ATP, ATP-cS, and unlabeled 8-azido-ATP, and by lack of competition ... 8-azido-[32P]ATP[aP]for 2 min at 4 °C, and this was followed by UV-induced covalent crosslinking of bound [a-32P]nucleo-tide. The proteins were separated by SDS ⁄ PAGE, and ABCFig. 3. ATP inhibits...