Premium
The adsorption of lysozymes: A model system
Author(s) -
Hansen J.,
Ely K.,
Horsley D.,
Herron J.,
Hlady V.,
Andrade J. D.
Publication year - 1988
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19880170110
Subject(s) - lysozyme , x ray photoelectron spectroscopy , adsorption , chemistry , protein adsorption , substrate (aquarium) , borosilicate glass , chemical engineering , materials science , organic chemistry , biochemistry , oceanography , engineering , geology
Hen egg white lysozyme was adsorbed onto clean borosilicate glass and n‐pentyl silane‐treated glass surfaces. Both modified (reductively methylated) and native lysozyme were studied. Variable angle X‐ray photoelectron spectroscopy (VA‐XPS) suggested differences in the nature of the adsorbed layer depending on substrate properties, as well as on degree of methylation of the protein. Adsorbed film thickness (as measured in the dehydrated state by XPS) ranged from 14 Å on hydrophilic glass to 25 Å on the hydrophobic surface. Degree of surface coverage ranged from 45% on the hydrophobic to 69% on the hydrophilic surface. The results suggest that lysozyme unfolds to a greater extent and covers more surface on the hydrophilic glass, possibly due to strong electrostatic interactions at the pH 7.4 conditions used in the study. An analysis of the surface structure of native hen lysozyme by molecular graphics has also been performed, suggesting that adsorption on hydrophobic surfaces should occur via the hydrophobic patch opposite the enzyme active site cleft. A comparison with human lysozyme has also been made using total internal reflection fluorescence (TIRF) spectroscopy to measure protein adsorption on model surfaces. The two proteins have significantly different interfacial properties.