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Surface‐dependent conformations of human plasma fibronectin adsorbed to silica, mica, and hydrophobic surfaces, studied with use of Atomic Force Microscopy
Author(s) -
Bergkvist Magnus,
Carlsson Jan,
Oscarsson Sven
Publication year - 2002
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.10423
Subject(s) - mica , materials science , adsorption , molecule , intermolecular force , intramolecular force , ionic bonding , crystallography , protein adsorption , chemical physics , chemical engineering , polymer , chemistry , stereochemistry , composite material , ion , organic chemistry , engineering
Abstract Human plasma fibronectin (Fn) is a large flexible protein stabilized by intermolecular ionic interactions forming a compact structure. On altering solution conditions, the structure can revert to a more expanded state, thereby exposing previously hidden domains (e.g., cell‐binding sites). Electron microscopy images of Fn air‐sprayed onto mica surfaces show elongated protein structures, indicating a surface‐induced structural change. This makes it interesting to investigate the influence of surface properties on the structure of adsorbed Fn. We have used intermittent‐contact Atomic Force Microscopy to investigate the structure of Fn adsorbed onto mica, silica, and methylated silica surfaces. We observed that on silica surfaces, which is hydrophilic, most (70%) of the molecules had an elongated structure with partial intramolecular chain interactions, compare to molecules adsorbed on hydrophobic, methylated surfaces, where a compact structure predominated (70%). On mica surfaces, both compact and elongated protein structures were observed, with a slight preference for the elongated form (53%). Results show that surface physical properties influence the molecular structure of fibronectin on adsorption, which could provide useful information in understanding surface‐induced in vivo responses. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 349–356, 2003