(458d) A Fractal Analysis of the Binding Kinetics of the Heat-Shock Protein Chaperone Dnak on a Spr Biosensor Surface

A fractal analysis is presented for the binding kinetics of the Heat-Shock Protein Chaperone DnaK in unstressed and stressed Escherichia coli cell lysate to anti-DnaK on a surface plasmon resonance (SPR) biosensor chip surface or by ELISA (Vostiar et al., 2003). The binding kinetics is described by either a single-, dual-, or a triple-fractal analysis. As expected, the levels of chaperone DnaK expressed in stressed Escherichia coli cell lysate is higher than that expresed in unstressed Escherichia coil cel lysate. There is a change in the binding mechanism as one goes from a single- to a dual- to a triple-fractal analysis. The analysis provides values of the binding rate coefficient, k and the degree of heterogeneity on the sensing surface. Furthermore, the analysis provides fresh physical insights into the binding of Escherichia coli chaperone DnaK to anti-DnaK under stressed and heat-stressed conditions. It is of interest to note that for the unstressed Escherichia coli cell culture analysis of DnaK by ELISA, there is a significant amount of variation in the DnaK concentration with time. It is this dilute nature of the DnaK concentration in solution that requires a higher degree of fractal analysis (dual- or triple-) to adequately model the binding kinetics.