Binding site integrity

Binding assays, e.g.. Binding site integrity. Sometimes limited precision, but... 

Four examples will now be given of such mechanistic biomarker assays that can give integrative measures of toxic action by pollutants, all of which have been described earlier in the text. Where the members of a group of pollutants share a common mode of action and their effects are additive, TEQs can, in principle, be estimated from their concentrations and then summated to estimate the toxicity of the mixture. In these examples, toxicity is thought to be simply related to the proportion of the total number sites of action occupied by the pollutants and the toxic effect additive where two or more compounds of the same type are attached to the binding site. 

Protein 4.1, a globular protein, binds tightly to the tail end of spectrin, near the actin-binding site of the latter, and thus is part of a protein 4.1-spectrin-actin ternary complex. Protein 4.1 also binds to the integral proteins, glycophorins A and C, thereby attaching the ternary complex to the membrane. In addition, protein 4.1 may interact with certain membrane phospholipids, thus connecting the lipid bilayer to the cytoskeleton. 

Laman ID, Kors N, Heeney JL, et al. Fixation of cryo-sections under HIV-1 inactivating conditions integrity of antigen binding sites and cell surface antigens. Histochemistry 1991 96 177-183. 

It therefore appears that for at least domains 4 and 6, hCP possesses metal binding sites in addition to the six integral copper atoms. Binding of ferrous iron at these sites could result in its oxidation and its removal from the plasma or in the reduction of oxygen-based free radicals. Binding of copper could result in its transport through the plasma (vide infra). 

An alternative mechanism for loss of membrane integrity is via the solubilization of phospholipids by thionins." This revised version of the carpet model is based on the observation of a conserved binding site for phospholipids head groups in thionins, their tendency to form oligomers," " and small-angle X-ray scattering... 

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