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Human Serum Proteins (human + serum_protein)
Selected AbstractsAdduct-forming tendencies of cationic triarylmethane dyes with proteins: Metabolic and toxicological implicationsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2004Özden Tacal Abstract The formation of colorless adducts by four cationic triarylmethane dyes (TAM+s), methyl green (MeG+), malachite green (MG+), pararosaniline (PR+), and crystal violet (CV+) was studied spectrophotometrically at 25°C, in 50 mM 3-(N-morpholino)propanesulfonic acid (MOPS) buffer (pH 8), by monitoring the loss in TAM+ color in the absence and presence of human serum proteins as potential addends. Unfractionated serum caused a rapid bleaching of MeG+ and MG+, while PR+ and CV+ were unaffected. Sephacryl S200 HR chromatographic screening of the serum revealed two composite peaks of MeG+ -bleaching activity. The major peak (Mr range, 40,000,130,000) overlapped with and extended on either side of the albumin peak. The minor peak corresponding to ca. 10% of the total MeG+ -bleaching capacity had Mr > 230,000. MG+ -bleaching activity dominated the entire chromatographic profile and implicated a multitude of minority proteins with a high capacity to form colorless MG adducts. It is concluded that highly electrophilic TAM+s such as MeG+ and MG+ must be quantitatively trapped in the form of dye,protein adducts in biological fluids and that the primary in vivo effects (e.g. toxicity) of such dyes most likely arise from ligand-type effects on multiple protein targets. Mechanisms that call for unmodified TAM+ structure (radical-mediated redox changes, DNA intercalation) may be more relevant to the in vivo impact of dyes such as PR+ and CV+ that have a lower tendency to form adducts. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:253,256, 2004 Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20034 [source] Determination of binding constants and stoichiometries for platinum anticancer drugs and serum transport proteins by capillary electrophoresis using the Hummel-Dreyer methodJOURNAL OF SEPARATION SCIENCE, JSS, Issue 2 2005Alexander V. Rudnev Abstract A CE method has been developed to evidence and quantitatively characterize the interaction between platinum-based antitumor drugs and human serum proteins. This method is a variant of affinity CE modified regarding both experimental setup and data treatment so as to measure the peaks (or vacancies) that correspond to the bound drug when it slowly binds to the protein. Using the formalism of the Hummel-Dreyer method and cisplatin and oxaliplatin as test compounds, a protocol for determining albumin and transferrin binding constants and stoichiometries, including (and distinguished by) 48 hours of incubation of the reaction mixture, was elaborated. Relative affinities of drugs toward different proteins in aqueous solution at physiological pH, chloride concentration, and temperature were compared in terms of overall binding constants and numbers of drug molecules attached to the protein. The results indicate that both platinum drugs bind to albumin more strongly than to transferrin, supporting the concept that the albumin fraction is a major drug supply route for chemotherapeutical needs. From a comparison with the binding parameters measured previously for cisplatin by other methods, conclusions were drawn about the validity of CE as a simple and convenient method for assaying protein-drug reactions with slow kinetics. [source] Effects of zinc and copper on adhesion and hemagglutination of Prevotella intermedia and Prevotella nigrescensMOLECULAR ORAL MICROBIOLOGY, Issue 6 2005M. Tamura This study investigated the mechanism of protein attachment to the surface of the putative periodontal pathogens Prevotella intermedia and Prevotella nigrescens in artificial gingival crevicular fluid, and ways to increase protein attachment to the bacterial cells. The effects of cations on protein attachment, bacterial adhesion, and hemagglutination were examined, and cation-binding components on both bacterial species were identified. The presence of cations, especially zinc, copper and cerium, increased attachment of human serum proteins to both bacterial species. In contrast, the presence of hydrophobic inhibitors or sugars had little effect. Protein attachment was reduced by heat treatment of the bacterial cells. Pretreatment of bacteria with human serum proteins inhibited adhesion of both species to buccal epithelial cells and hemagglutination. These effects were enhanced by the presence of zinc and copper during pretreatment. Using a chelating column, specific zinc- and copper-binding proteins were identified on the surfaces of both bacterial species. [source] Comparison of Nonmetal and Metal Hydrophilic Photosensitizer, ATX-S10 (Na) and ATN-2, Binding with Human Serum Proteins Using Spectrophotometry,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2004M. Yamaguchi ABSTRACT Intermolecular interactions of human serum proteins with a hydrophilic nonmetalloporphyrin, 13,17-bis(1-carboxy-propionyl)carbomoylethyl-8-ethenyl-2-hydroxy-3-hydroxy-iminoethylidene-2,7,12,18-tetramethylporphyrin sodium salt (ATX-S10 (Na)), or a hydrophilic gallium-metalloporphyrin, diethylenetriamine pentaacetic acid ester of 2-[1-(2-hydroxyethoxy)ethyl]-4-vinyl-deuteroporphyrin (IX) Ga complex (ATN-2), were investigated using spectrophotometry. ATX-S10 (Na) caused a bathochromic shift with albumin, high-density lipoprotein and low-density lipoprotein, but little or no shift was observed with hemopexin, transferrin and immuno-globulin G. In contrast, ATN-2 displayed a bathochromic shift only with hemopexin. These results suggest that the association energy of ATX-S10 (Na) with albumin might be slightly greater than that with lipoproteins and that of ATN-2 with hemopexin might be greater than that with other serum proteins. [source] | ||||||||||