Identification, purification and partial characterization of low molecular weight protein inhibitor of Na+/K+-ATPase from pulmonary artery smooth muscle cells
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We have identified a novel endogenous low mol wt. (15.6 kDa) protein inhibitor of Na+/K+-ATPase in cytosolic fraction of bovine pulmonary artery smooth muscle cells. The inhibitor showed different affinities toward the α2β1 and α1β1 isozymes of Na+/K+-ATPase, where α2 is more sensitive than α1. The inhibitor interacted reversibly to the E1 site of the enzyme and blocked the phosphorylated intermediate formation. Circular dichroism study suggests that the inhibitor causes an alteration in the confirmation of the enzyme.
KeywordsNa+/K+-ATPase Protein inhibitor Ouabain Pulmonary smooth muscle cells
Financial assistance from the Council of Scientific and Industrial Research (Govt. of India) and DST-PURSE program of the University of Kalyani is greatly acknowledged.
Conflict of interest
There is no conflict of interest.
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