Abstract:The maize cytosolic 70 kD stress protein (HSC70) has been purified by a two-step procedure employing affinity
chromatography on ATP-agarose followed by DEAE52 ion-exchange chromatography. Using a biotinylated
cauliflower calmodulin (CAM) gel-overlay technique in the presence of 1 mmol/L Ca2+ , the HSCT0 could
bind to CAM. No band was shown on sodium dodecyl sulfate-polyacrylamide gel overlayed with biotinylated
cauliflower CaM when 1 mmoL/L Ca2+ was replaced by 5 mmol/L EGTA. It indicated that the binding of
HSC70 to CaM was dependent on Ca2+. The purified HSC70 inhibited the activity of CaM-dependent NADK
and the degree of inhibition increased with augmentation of the HSC70, which appeared to be typically
characteristic to CaM- binding protein.