title: Thermotropic properties of human erythrocyte membrane proteins as affected by hydroxychloroaromatic compounds.
abstract: The thermal stability of the anion transport protein (band 3) and other proteins of the human erythrocyte membrane, as influenced by hydroxychloroaromatic (HO-Cl2-Ar) compounds, was studied by differential scanning calorimetry. Various hydroxychlorodiphenyl ethers (HO-Clx-DPEs) and hexachlorophene, but not pentachlorophenol, caused a marked decrease in the thermal stability of band 3. Most of the other calorimetric transitions of the erythrocyte membrane were only slightly affected. The activity of HO-Clx-DPEs toward lowering the transition temperature of band 3 generally increased with the degree of chlorination, and was somewhat dependent on the position of hydroxyl substitution. At higher concentrations of HO-Clx-DPEs, there was a decrease in the enthalpy change and a broadening of the endothermic transition of band 3. The order of effectiveness of these compounds, as determined from band 3 denaturation temperatures, was similar to the order of potency previously observed for hemolysis of human erythrocytes.
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives; D001798:Blood Proteins / Q000187:drug effects*; D002152:Calorimetry, Differential Scanning; D002733:Chlorophenols / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000187:drug effects* / Q000378:metabolism; D006582:Hexachlorophene / Q000097:blood / Q000494:pharmacology*; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000097:blood / Q000494:pharmacology*; D008565:Membrane Proteins / Q000097:blood*; D010416:Pentachlorophenol / Q000097:blood / Q000494:pharmacology*; D010647:Phenyl Ethers / Q000097:blood / Q000494:pharmacology*; D011489:Protein Denaturation / Q000187:drug effects; D013816:Thermodynamics
chemical_list: D001798:Blood Proteins; D002733:Chlorophenols; D006843:Hydrocarbons, Chlorinated; D008565:Membrane Proteins; D010647:Phenyl Ethers; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D010416:Pentachlorophenol; D006582:Hexachlorophene; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid