Abstract
To understand interactions between protein molecules and inorganic substrates, we succeeded in observing individual fluorescence labeled lysozyme (F-lysozyme) molecules diffusing in the vicinity of the surfaces of SiO_2 and glass substrates, in real time, by a single molecule visualization technique. Our results indicated that diffusion coefficients of F-lysozyme molecules on SiO_2 and glass substrates are 3-4 orders of magnitude smaller than those in solution. In addition, number of F-lysozyme molecules observed per μm^2 for one second on a SiO_2 substrate is about 20 times smaller than that on a glass substrate. These results show that the activation energy of diffusion of F-lysozyme molecules on a SiO_2 substrate is almost same as that on a glass substrate, in contrast, the activation energy of desorption of F-lysozyme molecules from a SiO_2 substrate is smaller than that from a glass substrate. These experimental findings were compared and examined with those of molecular dynamics simulations to establish computer simulation technologies.
