Gating mechanism

Future development of SAM-based analytical technology requires expansion of the size and shape selectivity of template stmctures, as well as introduction of advanced chemical and optical gating mechanisms. An important contribution of SAMs is in miniaturization of analytical instmmentation. This use may in turn have considerable importance in the biomedical analytical area, where miniature analytical probes will be introduced into the body and target-specific organs or even cell clusters. Advances in high resolution spatial patterning of SAMs open the way for such technologies (268,352). 

During excitation, ion channels open and close and a few ions flow 98 Gating mechanisms for Na+ and K+ channels in the axolemma are voltage-dependent 98... 

Miyazawa, A., Fujiyoshi Y. and Unwin, N. Structure and gating mechanism of the acetylcholine receptor pore. Nature 423,949-955,2003. 

Ballesteros, J. A. and Weinstein, H. (1992) The role of Pro/Hyp-kinks in determining the transmembrane helix length and gating mechanism of a Leu-zervamicin channel. Biophys. J. 62,110-111. 

Dorsal raphe Main serotonin (5-HT)-containing neurons that project through the brain. Other raphe neurons project down the spinal cord where they act as a gating mechanism for pain perception from the periphery. Main activity is in the regulation of mood, anxiety, sexual behaviour, sleep. 

The cell uses various mechanisms to trigger and regulate the flow of ions through ion channels. Ion flow is subject to the following gating mechanisms, according to the natme of the ion channel ... 

FIGURE 8. Current model for the gating mechanism in the CorA transporter. Left closed conformation with the magnesium binding sites in the sensor occupied. Right postulated open conformation allowing ion transport into the ceU. Adapted by permission of MacmiUan Publishers Ltd. from Reference 71... 

The S. lividans K+ channel is not voltage gated. Voltage-gating mechanisms must be learned from study of other channels The voltage-dependent K+ channels from the rat have an a4P4 composition. The a and (3 subunits coassemble in the endoplasmic reticulum and remain as a permanent complex,3703 After insertion into the plasma membrane the a subunits form a channel as in Fig. 8-21. However, an additional intracellular domain of... 

By analogy with other calcium-binding proteins, it is expected that the Ca2+-bound intestinal protein is then able to interact with some receptor protein. Suggestions have been made for interaction with alkaline phosphatase or carbonic anhydrase, but another possibility is that the calcium-bound protein is able to activate a gating mechanism for the transport of calcium. 

Toyoshima, C., Nomura, H., Tsuda, T., 2004, Lumenal gating mechanism revealed in calcium pump crystal structures with phosphate analogues. Nature 432, 361-368. 

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