Ca(2+) influx via store-operated Ca(2+) release activated Ca(2+) (CRAC) channels represents a main signaling pathway for T-cell activation as well as mast-cell degranulation. The ER-located Ca(2+)-sensor, STIM1 and the Ca(2+)-selective ion pore, Orai1 in the membrane are sufficient to fully reconstitute CRAC currents. Their identification, but even more the recent structural resolution of both ...

In previous chapters, the synthesis of a highly hydrogen selective membrane formed by the deposition of a silica layer on top of a Vycor glass substrate was discussed. In this chapter, the preparation of a composite membrane using a porous alumina support is described. This membrane showed a high hydrogen permeance of the order of 10 mol m s Pa at 873 K with selectivity of hydrogen over CH4, CO...

Celecoxib, a selective cyclo-oxygenase – 2 inhibitor has been recommended orally for the treatment of arthritis and osteoarthritis. Long term oral administration of celecoxib produces serious gastrointestinal side effects. Therefore the aim of the present investigation was to assess the potential of nanosized emulsion formulations for transdermal delivery of celecoxib (CXB), to reduce the side ...

The aim of this study is to investigate how the semisynthetic bile acid; 3alpha,7alpha-dihydroxy-12-keto-5beta-cholanate, also known as 12-monoketocholic acid (MKC) influences the ileal permeation of the antidiabetic drug gliclazide in healthy and diabetic rats. Male Wistar rats were divided into 10 groups (n = 32), of which 5 comprised healthy rats (1 to 5) and 5 diabetic rats (6 to 10). Group...

Recent determination of the molecular structures of potassium andmechanosensitive channels from x-ray crystallography has led to arenewed interest in ion channels. The challenge for permeation modelsis to understand the functional properties of channels from the availablestructural information. Here we give a critical review of the three maincontenders, namely, continuum theories, Brownian dyna...

The development of processes based on the integration of new technologies is of growing interest to industrial catalysis. Recently, significant efforts have been focused on the design of catalytic membrane reactors to improve process performance. In particular, the use of membranes, that allow a selective permeation of water from the reaction mixture, positively affects the reaction evolution b...

TRPV5 is unique within the large TRP channel family for displaying a high Ca2+ selectivity together with Ca2+-dependent inactivation. Our study aims to uncover novel insights into channel gating through in-depth structure-function analysis. We identify an exceptional tryptophan (W583) at the terminus of the intracellular pore that is unique for TRPV5 (and TRPV6). A combination of site-directed ...

"Real time" molecular dynamics simulations of water permeation through human aquaporin-1 (AQP1) and the bacterial glycerol facilitator GlpF are presented. We obtained time-resolved, atomic-resolution models of the permeation mechanism across these highly selective membrane channels. Both proteins act as two-stage filters: Conserved fingerprint [asparagine-proline-alanine (NPA)] motifs form a se...