Abstract
The adsorption kinetics exhibited by selected charge mutants of bacteriophage T4 lysozyme at silanized silica surfaces were monitored with in situ ellipsometry. Mutant lysozymes were produced by substitution of lysine with glutamic acid. Each substitution resulted in a decrease in the net charge of the protein by 2 units. The wild type lysozyme of net charge +9, and two mutants of net charge + 7 and +5 were obtained from Escherichia coli strain RR1. Adsorption kinetics recorded at hydrophilic and hydrophobic interfaces were compared to the kinetic behavior predicted by two simple models for protein adsorption. One allowed for reversible adsorption followed by conversion to an irreversibly adsorbed form. The second model allowed for irreversible adsorption into one of two states directly from solution. Both models suggested that proteins apparently adsorbed at the interfaces more tightly and occupied a greater interfacial area with substitution of lysine with glutamic acid. These effects were related to the location of the substitutions relative to other mobile, solvent-exposed charged residues of the protein, and not to net charge.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.