AJP - Cell Physiology, Vol 251, Issue 5 721-C726, Copyright © 1986 by American Physiological Society

ARTICLES

Resolution of apical from basolateral membrane of shark rectal gland

W. P. Dubinsky and L. B. Monti

Membrane fractions were isolated from the rectal gland of Squalus acanthias using differential centrifugation and a sucrose gradient run in the presence of 1 M KBr. Using the basolateral membrane marker Na+-K+-ATPase, we obtained a sixfold purification with the most highly purified fraction from the gradient (sp act = 336 +/- 37 mumol X mg protein-1 X h-1). Electrogenic Br- transport was used as a marker activity of the apical membrane, which enabled the identification and purification of a membrane fraction that is highly resolved from the basolateral membrane. The most active fraction was purified approximately 50-fold compared with the crude homogenate. In this fraction, the specific activity of electrogenic anion transport was 296 +/- 87 nmol X mg protein-1 X min-1, whereas the ATPase was only 17.6 +/- 5.7 mumol X mg protein-1 X h-1, representing about a 4-5% contamination of the apical fraction with the basolateral membrane.

This article has been cited by other articles:

				J. D. Zeidel, J. C. Mathai, J. D. Campbell, W. G. Ruiz, G. L. Apodaca, J. Riordan, and M. L. Zeidel Selective permeability barrier to urea in shark rectal gland Am J Physiol Renal Physiol, July 1, 2005; 289(1): F83 - F89. [Abstract] [Full Text] [PDF]

				W. P. Dubinsky, O. Mayorga-Wark, and S. G. Schultz Colocalization of glycolytic enzyme activity and KATP channels in basolateral membrane of Necturus enterocytes Am J Physiol Cell Physiol, December 1, 1998; 275(6): C1653 - C1659. [Abstract] [Full Text] [PDF]