George P. Hess

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In the presence of acetylcholine, the nicotinic acetylcholine receptor undergoes two rapid conformational changes: one in the 1-ms time region, leading to the formation of a transmembrane channel and signal transmission between cells, and the other in the 100-ms time region, leading to an inactive "desensitized" form with altered ligand-binding properties.(More)
Newly synthesized photolabile derivatives of glutamate, caged glutamate, that release free glutamate on a microsecond time scale after a pulse of UV laser light are described. 2-Nitrobenzyl derivatives were attached to the amino or carboxyl groups of glutamate. Substitution with a -CO2- group at the benzylic carbon accelerates the photolysis reaction when(More)
Recent studies have provided evidence for a role of protein phosphorylation in the regulation of the function of various potassium and calcium channels (for reviews, see refs 1, 2). As these ion channels have not yet been isolated and characterized, it has not been possible to determine whether phosphorylation of the ion channels themselves alters their(More)
The nicotinic acetylcholine receptor (AChR) controls signal transmission between cells in the nervous system. Abused drugs such as cocaine inhibit this receptor. Transient kinetic investigations indicate that inhibitors decrease the channel-opening equilibrium constant [Hess, G. P. & Grewer, C. (1998) Methods Enzymol. 291, 443-473]. Can compounds be found(More)
When a neurotransmitter binds to its specific receptor, the protein forms transmembrane channels through which ions flow, leading to changes in transmembrane voltage that trigger signal transmission between neurons. How do inhibitors affect this process? Interesting and extensive information comes from investigations of the acetylcholine receptor, the best(More)
The rhythmic contraction of the Caenorhabditis elegans pharynx is unique in that the network of 12 neurons, including two M3 neurons, that regulate the contraction is known. The neurotransmitters secreted by these cells, and the target cells responding to these chemical signals, are not known. Here, we describe an approach to obtain this missing information(More)
Two molecular processes, the binding of acetylcholine to the membrane-bound acetylcholine receptor protein and the receptor-controlled flux rates of specific inorganic ions, are essential in determining the electrical membrane potential of nerve and muscle cells. The measurements reported establish the relationship between the two processes: the(More)
Effects of cocaine on the muscle nicotinic acetylcholine receptor were investigated by using a chemical kinetic technique with a microsecond time resolution. This membrane-bound receptor regulates signal transmission between nerve and muscle cells, initiates muscle contraction, and is inhibited by cocaine, an abused drug. The inhibition mechanism is not(More)