Accession Number : ADA187300

Title :   Effect of Electric Fields on Membrane Bound (Na,K)-ATPase.

Descriptive Note : Annual rept. 1 Dec 86-30 Sep 87,

Corporate Author : JOHNS HOPKINS UNIV BALTIMORE MD DEPT OF BIOLOGICAL CHEMISTRY

Personal Author(s) : Tsong, Tian Y

PDF Url : ADA187300

Report Date : 06 Nov 1987

Pagination or Media Count : 5

Abstract : A protein of a cell membrane is structurally sensitive to an electric field because of its charges, helix dipoles and polarizability. When such a protein is exposed to an applied oscillating electric field, the conformational oscillation of the protein can be coupled to driving an endergonic reaction. We have investigated how such an interaction between the sodium, potassium +(Na,K)-ATPase of human erythrocytes and an a.c. field leads to active pumping of K+ and Na against their respective concentration gradient. Experiments done in this past year establish that optimum frequency of rubidium Rb+ (an equivalent of K+) occurs at 1.0 kHz and that for Na+ efflux at 1 MHz or higher. The optimum voltage for both pumps is 20 V/cm. An electroconformational coupling model is proposed and the above data analyzed according to the model. In the continuation years we will study the relationship between stimulating voltage and optimum frequency, and vise versa. Its molecular mechanisms will be investigated and more quantitative analysis performed. Keywords: Electrophysiology; Biochemistry.

Descriptors :   *ELECTRIC FIELDS, *ELECTROPHYSIOLOGY, *PHOSPHORUS TRANSFERASES, BIOCHEMISTRY, CELLS(BIOLOGY), CONCENTRATION(COMPOSITION), COUPLING(INTERACTION), ERYTHROCYTES, FREQUENCY, GRADIENTS, HUMANS, MEMBRANES(BIOLOGY), MODELS, MOLECULAR PROPERTIES, OPTIMIZATION, OSCILLATION, POLARIZATION, POTASSIUM, PROTEINS, PUMPING, QUANTITATIVE ANALYSIS, RUBIDIUM, SODIUM, VOLTAGE, CATIONS, ALTERNATING CURRENT, STIMULATION(PHYSIOLOGY)

Subject Categories : Biochemistry
      Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE