In this thesis, the mechanisms underlying anesthesia and the adsorption of proteins on solid surfaces have been studied using the method of molecular dynamics simulations. It is generally assumed that biological membranes are the site of anesthetic action. However, there is no consensus whether anesthetics act directly by binding to membrane proteins, thereby inhibiting their function, or indirectly by modulating the physical properties of the lipid part of the membrane. In the simulations presented here, distinct changes of lipid bilayer properties in response to the presence of alkanols, a group of anesthetics, have been observed. An anesthetic-induced shift of the equilibrium between different membrane protein conformations, modeled by simple geometric shapes, has been found. In simulations with the ion channel gramicidin A embedded in a lipid bilayer, alkanols distributed inhomogeneously in the bilayer, with almost no alkanol molecules residing in close vicinity to the gramicidin. These results provide evidence for an indirect mode of anesthetic action. Spontaneous protein adsorption on solid-liquid interfaces is the first step in the formation of biofilms. Here, a coarse-grained molecular dynamics scheme has been applied to study this complex process at high resolution, but still reaching the necessary time and length scales. Changes in protein structure and dynamics after adsorption and preferred orientations of proteins on the surface were observed.
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