Robert M Stroud
University of California, USA
Posters & Accepted Abstracts: Biochem Anal Biochem
Transmembrane channels and facilitators can be highly selective in mediating the transport of amino acids, nutrients and ions across membranes �??downhill�??, down their concentration gradient. Channels are often activated by voltage changes detected by multiple arginine side chains that interact with a charge transfer site. Channels respond to ligands that open and close channels, or to ions like Ca++ that allosterically tune the response to voltage. Transporters and pumps can drive and concentrate nutrients or ions �??uphill�?? (energetically) across membranes achieving gradients of >1000:1 driven by �??downhill�?? movement of other coupled ions, protons, metabolites or electrochemical gradients or in pumps driven by ATP hydrolysis. Electrochemical gradients are typically the driving force for packaging the amino acid glutamate in glutamatergic synapses in the brain. I will select a recent topical example to illustrate the remarkable discoveries being made in membrane protein biology, and to illustrate the opportunities for new drug targets.