Tris receptors

The biological properties of dioxin include an ability to bind to a protein known as the AH (aromatic hydrocarbon) receptor Dioxin IS not a hydrocarbon but it shares a certain structural property with aromatic hydrocarbons Try constructing molecular models of dioxin and anthracene to see these similarities... 

The initial direction of transport of pollutants from their source is determined by the wind direction at the source. Air pollutant concentrations from point sources are probably more sensitive to wind direction than any other parameter. If the wind is blowing directly toward a receptor (a location receiving transported pollutants), a shift in direction of as little as 5° (the approximate accuracy of a wind direction measurement) causes concentrations at the receptor to drop about 10% under unstable conditions, about 50% under neutral conditions, and about 90% under stable conditions. The direction of plume transport is very important in source impact assessment where there are sensitive receptors or two or more sources and in trying to assess the performance of a model through comparison of measured air quality with model estimates. 

The open channel has in most cases a selective permeability, allowing a restricted class of ions to flow,for example Na+, K+, Ca++ or Cl- and, accordingly, these channels are called Na+-channels, K+-channels, Ca -channels and Cr-channels. In contrast, cation-permeable channels with little selectivity reject all anions but discriminate little among small cations. Little is known about the structures and functions of these non-selective cation channels [1], and so far only one of them, the nicotinic acetylcholine receptor (nAChR, see Nicotinic Receptors), has been characterized in depth [2, 3]. The nAChR is a ligand-gated channel (see below) that does not select well among cations the channel is even permeable to choline, glycine ethylester and tris buffer cations. A number of other plasma... 

Class IIHLA molecules are expressed on the surface of antigen-presenting cells. They play a key role in presentation of processed linear peptide antigens of at least nine amino acids to T cells. Antigen is bound to the HLA antigen binding cleft formed by the a and 3 chains of the HLA class II molecule. This tri-molecular HLA-antigen complex binds in turn to the variable portion of the T-cell receptor. 

Miller LG, Greenblatt DJ, Barnhill JG, et ah Benzodiazepine receptor binding of tri-azolobenzodiazepines in vivo increased receptor number with low-dose alprazolam. J Neurochem 49 1595-1601, 1987... 

M -Dialkyldiazacrown ethers and their precursors fcis(alkylamino) derivatives of tri- and tetraethylene glycols were prepared <96CCCC622>. New hydroxy-bearing dibenzo-azocrown ethers have been conveniently prepared utilizing l,3-Ws(2-formylphenoxy)-2-propanol and a diamine, followed by reduction of the intermediate diimine <96P1197>. Fluorescent photoinduced electron transfer sensor 5 with monoaza-18-crown-6 and guanidinium receptor units demonstrated a fluorescence with T -aminobutyric acid in a mixed... 

Any color signal received from the snbject will be rated by the spectral sensitivity of the eye. The physiological bases for this are three types of cone-shaped receptors on the human retina that are sensitive to red, green, and bine. The color measurement techniques have been established on this tri-colorimetric system. They simulate human perception by the relative extent to which the observer estimates the relative share of which of these three components contributes to his color impression from an object. 

In the case of competitive inhibition, the substrate is displaced by a substance which has greater affinity for the enzyme (or receptor protein) than its natural substrate. For example, a competitive inhibitor (or antagonist) will try to occupy the binding sites such that the enzyme is prevented from exerting its normal activity on the substrate. It is assumed here that the binding between inhibitor and... 

QUESTION How do you imagine that both a receptor antagonist and an uptake inhibitor would block the effects It would seem that if dopamine is involved, it would either be acting on a membrane receptor or inside, but not both. I would also like to ask a more specific question. You showed that the alpha MT protected effect could be reversed by dopa. And I think you imagined that that was because of dopamine formation. But have you tried dopamine agonists to see if they would antagonize either the protective effect of alpha methyltyrosine or, particularly, the protective effect of the dopamine antagonists to try to verily that those protective effects really have to do with blockade of a dopamine receptor as opposed to some other possibility ... 

Scheme 28. Modification of a tris(pyrazolyl)hydroborato ligand to a receptor for binding anions.

Quirion, R. Hammer, R.P., Jr Herkenham, M. and Pert, C.B. Phencyclidine (angel dust)/sigma "opiate" receptor Visualization by tri ti um-sensi ti ve film. Proc Natl Acad Sci USA 78 5881-5885, 1981a. 

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