Chiral stationary phases obtained by immobilization of HSA on [C8] and [C18] reversed-phases and on poly(1-vinylimidazole)-coated silica were tested to resolve DL-tryptophan, N-benzoyl-DL-phenylalanine, RS-oxazepam and RS-warfarin racemic mixtures. Parameters of enantioselectivity measured in HPLC are correlated to structural and solvation states for adsorbed HSA, evaluated by FTIR spectroscopy. HSA immobilized on [PVI]-anion-exchangers is highly selective.
View Article and Find Full Text PDFRaman microprobe spectrometry has been applied to the characterization of unstable species generated electrochemically at a microelectrode (radius in the 10 microm range). The ability of the spectroelectrochemical method to detect short-lived intermediates is directly related to its capability to probe small volumes. Raman microprobe spectrometry is appropriate for electrochemical applications because it allows the analysis of approximately 1 microm3 of solution.
View Article and Find Full Text PDFInteractions between proteins and clays perturb biological activity in ecosystems, particularly soil extracellular enzyme activity. The pH dependence of hydrophobic, hydrophilic, and electrostatic interactions on the adsorption of bovine serum albumin (BSA) is studied. BSA secondary structures and hydration are revealed from computation of the Amide I and II FTIR absorption profiles.
View Article and Find Full Text PDFSoils have a large solid surface area and high adsorptive capacities. To determine if structural and solvation changes induced by adsorption on clays are related to changes in enzyme activity, alpha-chymotrypsin adsorbed on a phyllosilicate with an electronegative surface (montmorillonite) has been studied by transmission FTIR spectroscopy. A comparison of the pH-dependent structural changes for the solution and adsorbed states probes the electrostatic origin of the adsorption.
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