Spatial variation of the charge and sulfur oxidation state in a surface gradient affects plasma protein adsorption
| Autor: | Bryon E. Wright, Yong Xue Ding, Vladimir Hlady, Seth Streitmatter |
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| Rok vydání: | 2010 |
| Předmět: |
Surface Properties
Kinetics Analytical chemistry Surface gradient Concentration effect Article Adsorption Oxidation state Monolayer Electrochemistry Humans General Materials Science Surface charge Spectroscopy Serum Albumin Total internal reflection fluorescence microscope Chromatography Chemistry Fibrinogen Surfaces and Interfaces Blood Proteins Condensed Matter Physics Silicon Dioxide Immunoglobulin G Oxidation-Reduction Sulfur |
| Zdroj: | Langmuir : the ACS journal of surfaces and colloids. 26(14) |
| ISSN: | 1520-5827 |
| Popis: | A gradient of negative surface charge based on the 1D spatial variation from surface sulfhydryl to mixed sulfhydryl-sulfonate moieties was prepared by the controlled UV oxidation of a 3-mercaptopropylsilane monolayer on fused silica. The adsorption of three human plasma proteins--albumin (HSA), immunoglobulin G (IgG), and fibrinogen (Fgn)--onto such a surface gradient was studied using spatially resolved total internal reflection fluorescence (TIRF) and autoradiography. Adsorption was measured from dilute solutions equivalent to 1/100 (TIRF, autoradiography), 1/500, and 1/1000 (autoradiography) of protein physiological concentrations in plasma. All three proteins adsorbed more to the nonoxidized sulfhydryl region than to the oxidized, mixed sulfhydryl-sulfonate region of the gradient. In the case of HSA, the adsorption contrast along the gradient was largest when the adsorption took place from more dilute protein solutions. Increasing the concentration to 1/100 of the protein plasma concentration eliminated the effect of the gradient on HSA adsorption and, to the lesser extent, on IgG adsorption. In the case of Fgn, the greatest adsorption contrast was observed at the highest concentration used. On the basis of adsorption kinetics, the estimated binding affinity of HSA for the sulfhydryl region was twice the affinity for the mixed sulfhydryl-sulfonate region of the gradient. For IgG and Fgn, the initial adsorption was transport-limited and the initial adsorption rates approached the computed flux of the protein to the surface. |
| Databáze: | OpenAIRE |
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