UBC Theses and Dissertations
Studies on sodium and potassium ion activated adenosine trihosphatase Pang, Yew Choi
The Na⁺K⁺-activated ATPase was obtained from the rectal, glands of dog fish. Optimum conditions for extraction of the membrane bound enzyme into solution and stabilization by glycerol was investigated, followed by attempts to purify the enzyme by affinity chromatography using insolubilized Concanavalin A, wheat germ agglutinin and a modified ATP molecule as affinity ligands. The structure and size of the enzyme as a macromolecule was characterized by a combination of the results from velocity sedimentation in an isokinetic sucrose gradient and gel filtration with Sepharose 6B. The sedimentation coefficient was found to be 5.0 S by velocity sedimentation, and the Stokes' radius was found to be 114Å by gel filtration. Using these data, the molecular weight of the intact enzyme was estimated to be 240,000. This is in good agreement with the molecular weight derived from sodium dodecyl sulfate gel electrophoresis obtained by other workers.
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