X-ray crystallographic studies on retinol-binding proteins
Abstract
Structural information for proteins that interact with retinoids or that mediate retinoid function(s) is critical to the understanding of the role(s) of natural or synthetic retinoids in physiology and medicine. X-Ray crystallographic studies of this class of proteins can provide the details necessary to understand retinoid recognition at the molecular level. Some of the steps involved in a structural determination can be briefly summarized as: (1) the protein must be isolated in relatively large quantity with a very high degree of purity, (2) protein crystals suitable for X-ray diffraction data collection are prepared, and (3) X-Ray diffraction data are collected. Once a high-resolution structure is determined, the structures of the protein complexed with ligand or ligand analogs are relatively straightforward to determine. This chapter describes some of the biochemical details of the process relevant only to the solution of the structure of retinol-binding protein. With the availability of these methods, the structural aspects of the specificity of the retinol-binding protein for its ligand as well as for its carrier protein transthyretin (TTR) can be probed. The three-dimensional structure of transthyretin that is found complexed with the retinol-binding protein in human serum has been determined. © 1990, Elsevier Inc. All rights reserved.