The charge density distribution of a protein has been refined experimentally. Diffraction data for a crambin crystal were measured to ultra-high resolution (0.54 A) at low temperature by using short-wavelength synchrotron radiation. The crystal structure was refined with a model for charged, nonspherical, multipolar atoms to accurately describe the molecular electron density distribution. The refined parameters agree within 25% with our transferable electron density library derived from accurate single crystal diffraction analyses of several amino acids and small peptides. The resulting electron density maps of redistributed valence electrons (deformation maps) compare quantitatively well with a high-level quantum mechanical calculation performed on a monopeptide. This study provides validation for experimentally derived parameters and a window into charge density analysis of biological macromolecules.
Accurate protein crystallography at ultra-high resolution: valence electron distribution in crambin.,Jelsch C, Teeter MM, Lamzin V, Pichon-Pesme V, Blessing RH, Lecomte C Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3171-6. PMID:10737790
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Jelsch C, Teeter MM, Lamzin V, Pichon-Pesme V, Blessing RH, Lecomte C. Accurate protein crystallography at ultra-high resolution: valence electron distribution in crambin. Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3171-6. PMID:10737790