Springer us jan 2001 (2 Ergebnisse)

Buch. Zustand: Neu. Neuware - Biophysical studies in the 1950ies and 1960ies led to the realization that the water permeability of certain biological membranes must be due to the presence of water transporting proteins. This hypothesis was confirmed in 1991 and 1992 with the pioneering discovery of the first molecular membrane water channel, CHIP28, by Agre and coworkers. This integral membrane protein, which is abundant in the erythrocyte membrane and in many epithelial cells, is now called aquaporin-1 or AQP1. Thus the terms water channel or aquaporin are synonymous. In July 2000 more than 200 researchers came together in Gothenburg, Sweden, for the `3rd International Conference on the Molecular Biology and Physiology of Water and Solute Transport' to discuss progress in this emerging research field. 58 different presentations from this conference are the basis for this book. Cumulatively, these 58 short chapters provide a balanced overview complementing numerous recent reviews in this field.…

Buch. Zustand: Neu. Neuware - Mitochondria from mammalian tissues possess an elaborate system for 2+ 2+ transporting Ca across their inner membrane which consists of Ca import, 2+ via the Ca uniporter, in response to the mitochondrial membrane 2+ + potential and of Ca release by an antiport system in exchange for H + 9,23 or Na (see Fig. l) . Because the uniporter is dependent upon the external 2+ 2+ 2+ 2+ Ca concentration ([Ca ]), mitochondria accumulate Ca until the [Ca ] o o 2+ decreases to the level at which the uniporter activity balances the Ca efflux. 2+ The [Ca ] at which the uniporter and efflux activities are equal is defined o the 'setpoint' andcorresponds to values between 0.3-3µM. 2+ Figure 1. The Ca transport system of the inner membrane of mammalian mitochondria. U, + 2+ + + uniporter. I, Na -independent efflux mechanism or Ca /2H exchanger. D, Na -dependent 2+ + efflux mechanism or Ca /2Na exchanger. PTP, permeability transition pore. FP, 11 flavoprotein. membrane potential. pH gradient. Adapted from .…