Isolation and Antigenic Characterization of Corn Mitochondrial F1-ATPase

Publisher Website
Google Scholar
Abstract
Corn mitochondrial F1-ATPase was purified from submitochondrial particles by chloroform extraction. Enzyme stored in ammonium sulfate at 4.degree. C was substantially activated by ATP, while enzyme stored at -70.degree. C in 25% glycerol was not. Enzyme in glycerol remained fully active (8-9 .mu.mol Pi released min-1 mg-1), while the ammonium sulfate preparations steadily lost activity over a 2-mo. storage period. The enzyme was cold labile, and inactivated by 4 min at 60.degree. C. Treatment with octylglucoside resulted in complete loss of activity, while vanadate had no effect on activity. The apparent subunit MW of corn mitochondrial F1-ATPase were determined by SDS [sodium dodecyl sulfate]-polyacrylamide gel electrophoresis to be 58,000 (.alpha.), 55,000 (.beta.), 35,000 (.gamma.), 22,000 (.delta.) abd 12,000 (.epsilon.). Monoclonal and polyclonal antibodies used in competitive binding assays demonstrated that corn mitochondrial F1-ATPase was antigenically distinct from the chloroplastic CF1 [coupling factor]-ATPases of corn and spinach. Monoclonal antibodies against antigenic sites on spinach CF1-ATPase .beta. and .gamma. subunits were used to demonstrate that those sites were either changed substantially or totally absent from the mitochondrial F1-ATPase.

This publication has 22 references indexed in Scilit: