Novel methods for studying lipids and lipases and their mutual interactionat interfaces. Part II. Surface sensitive synchrotron X-ray scattering

Monolayers of lipids have been studied for more than a century. During the past decade new insight into the field has resulted from the development of surface sensitive X-ray scattering methods utilizing synchrotron radiation : grazing-incidence X-ray diffraction (GIXD) and specular X-ray reflectivit y (XR). These novel methods provide direct microscopic information about th e systems in question and allow in situ investigations under near physiolog ical conditions. GIXD gives information about the in-plane lattice symmetry and structural parameters; XR provides the electron density profile across the interface. The molecular structure, e.g., present review describes the theory, experimental procedures and sample requirements for surface sensit ive X-ray scattering. An overview of recent results is presented as well, w ith special emphasis on biologically important systems, e.g., investigation s by GIXD and/or XR of lipid and protein structures at interfaces and of li pid/protein interactions. (C) 2001 Societe francaise de biochimie et biolog ic moleculaire/Editions scientifiques et medicales Elsevier SAS. All rights reserved.