The permeability of the lysosomal membrane to small ions |
| |
Authors: | Robert P Casey Marja Hollemans Joseph M Tager |
| |
Institution: | Laboratory of Biochemistry, B.C.P. Jansen Institute, University of Amsterdam, Plantage Muidergracht 12, 1018 TV Amsterdam The Netherlands |
| |
Abstract: | The permeability of the lysosomal membrane to small anions and cations was studied at 37°C and pH 7.0 in a lysosomal-mitochondrial fraction isolated from the liver of untreated rats. The extent of osmotic lysis following ion influx was used as a measure of ion permeancy. In order to preserve electroneutrality, anion influx was coupled to an influx of K+ in the presence of valinomycin, and cation influx was coupled to an efflux of H+ using the protonophore . Lysosomal lysis was monitored by observing the loss of latency of two lysosomal hydrolases.The order of permeability of the lysosomal membrane to anions was found to be and that to cations . These orders are largely in agreement with the lyotropic series of anions and cations.The implications of these findings for the mechanism by means of which a low intralysosomal pH is produced and maintained are discussed. |
| |
Keywords: | S-13 HEPES |
本文献已被 ScienceDirect 等数据库收录! |
|