A thermodynamic analysis of the effects of myelin basic protein (MBP) on DPPS and DPPG monolayers

Abstract

Myelin basic protein (MBP) relate to multiple sclerosis, experimental cerebral spinal cord inflammation and other diseases of the central nervous system. It has important biological significance for the study the diseases which related to the interaction between myelin basic proteins (MBP) and DPPS, DPPG. In this paper, we studied the interaction between molecules at the air/water interface by thermodynamic method and atomic force microscopy (AFM). Experiments show that the average molecular area increases when the protein is incorporated into lipid monolayer. By means of analyzing surface pressure-mean molecular area (π-A) curves, a linear mass conservation plot (i.e. protein amount vs. a matching amount of lipids) was obtained. In addition, the protein partition coefficient and the mixing ration between protein and lipid were calculated. When the surface pressure of the monolayer was 10mN/m, one MBP molecule could be combined with (58±4) DPPS and (37±6) DPPG molecules. The interaction between MBP and DPPG (or DPPS) to determine the nervous system of the disease has a good biophysical significance and medical value.