1egl
From Proteopedia
THE SOLUTION STRUCTURE OF EGLIN C BASED ON MEASUREMENTS OF MANY NOES AND COUPLING CONSTANTS AND ITS COMPARISON WITH XRAY STRUCTURES
Structural highlights
Function[ICIC_HIRME] Inhibits both elastase and cathepsin G. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA highprecision solution structure of the elastase inhibitor eglin c was determined by NMR and distance geometry calculations. A large set of 947 nuclear Overhauser (NOE) distance constraints was identified, 417 of which were quantified from twodimensional NOE spectra at short mixing times. In addition, a large number of homonuclear 1H1H and heteronuclear 1H15N vicinal coupling constants were used, and constraints on 42 chi 1 and 38 phi angles were obtained. Structure calculations were carried out using the distance geometry program DGII. These calculations had a high convergence rate, in that 66 out of 75 calculations converged with maximum residual NOE violations ranging from 0.17 A to 0.47 A. The spread of the structures was characterized with average root mean square deviations (<rmsd>) between the structures and a mean structure. To calculate the <rmsd> unbiased toward any single structure, a new procedure was used for structure alignment. A canonical structure was calculated from the mean distances, and all structures were aligned relative to that. Furthermore, an angular order parameter S was defined and used to characterize the spread of structures in torsion angle space. To obtain an accurate estimate of the precision of the structure, the number of calculations was increased until the <rmsd> and the angular order parameters stabilized. This was achieved after approximately 40 calculations. The structure consists of a welldefined core whose backbone deviates from the canonical structure ca. 0.4 A, a disordered Nterminal heptapeptide whose backbone deviates by 0.812 A, and a proteinasebinding loop whose backbone deviates up to 3.0 A. Analysis of the angular order parameters and inspection of the structures indicates that a hingebending motion of the binding loop may occur in solution. Secondary structures were analyzed by comparison of dihedral angle patterns. The high precision of the structure allows one to identify subtle differences with four crystal structures of eglin c determined in complexes with proteinases. The solution structure of eglin c based on measurements of many NOEs and coupling constants and its comparison with Xray structures.,Hyberts SG, Goldberg MS, Havel TF, Wagner G Protein Sci. 1992 Jun;1(6):73651. PMID:1304915^{[1]} From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
