Conformational changes and competitive adsorption between serum albumin and hemoglobin on bioceramic substrates

TitleConformational changes and competitive adsorption between serum albumin and hemoglobin on bioceramic substrates
Publication TypeJournal Article
Year of Publication2017
AuthorsGruian C.M, Rickert C., Nicklisch S.CT, Vanea E., Steinhoff H.J, Simon S.
JournalChemphyschem
Volume18
Pagination634-642
Date Published2017/03
Type of ArticleArticle
ISBN Number1439-4235
Accession NumberWOS:000397578500008
Keywordsbioactive glass; bioceramics; bovine serum albumin; electron-paramagnetic-resonance; EPR spectroscopy; horse hemoglobin; inflammatory responses; net-charge; protein adsorption; pulsed electron; spin; spin labeling; sulfhydryl-groups; surface science; volumetric interpretation
Abstract

Traditional methods to analyze interactions and conformational changes of proteins adsorbed onto biomaterials are limited by the protein's associations with the substrate material and the complexity of the surrounding media. We have used EPR spectroscopy in combination with site-directed spin labeling (SDSL) to investigate single protein and competitive adsorption kinetics of horse hemoglobin (Hgb) and bovine serum albumin (BSA) on a silica-calcium-phosphate bioceramic substrate. Combined continuous wave and pulsed (DEER) EPR techniques were employed to monitor local mobility/flexibility changes within the proteins and tertiary structure dynamics upon adsorption. An alternate labeling technique was introduced to allow for specific quantification of each protein adsorbed to the bioceramic surface. We show that at buffer pH7.4 and 4.7 the amount of adsorbed hemoglobin was increased by a factor of 4-5 compared with BSA. The tertiary structure of hemoglobin was strongly affected upon adsorption, leading to a dissociation of the tetrameric molecule into monomers or dimers. When the bioceramic substrate was previously functionalized with a layer of BSA, dissociation was reduced by 71% compared with the untreated surface, indicating a primer effect of BSA for better adhesion of the globular hemoglobin.

DOI10.1002/cphc.201600886
Short TitleChemPhysChem
Student Publication: 
No