ADSORPTION-KINETICS OF WILD-TYPE AND 2 SYNTHETIC STABILITY MUTANTS OFT4 PHAGE LYSOZYME AT SILANIZED SILICA SURFACES

The adsorption kinetics exhibited by the wild type and two synthetic s tability mutants of bacteriophage T4 lysozyme at silanized silica surf aces were monitored with in situ ellipsometry, Mutant lysozymes purifi ed from Escherichia coil strain RRI were produced by substitution of t he isoleucine at amino acid position three with cysteine and tryptopha n, yielding proteins of greater and lower thermal stability than that of the wild type, Adsorption kinetics were measured over a period of 8 h and interpreted with reference to mechanisms allowing for binding i nto one of two states, characterized by different binding strengths, E ach interpretation suggested that a protein of lower structural stabil ity would more readily undergo a structural change at the interface, a ll other things being equal, and this change was more pronounced on hy drophilic than on hydrophobic surfaces. (C) 1996 Academic Press, Inc.