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Title: The NMR structure of cyclosporin A bound to cyclophilin in aqueous solution

Abstract

Cyclosporin A bound to the presumed receptor protein cyclophilin was studied in aqueous solution at pH 6.0 by nuclear magnetic resonance spectroscopy using uniform {sup 15}N- or {sup 13}C-labeling of cyclosporin A and heteronuclear spectral editing techniques. With an input of 108 intramolecular NOEs and four vicinal {sup 3}J{sub HN{alpha}} coupling constants, the three-dimensional structure of cyclosporin A bound to cyclophilin was calculated with the distance geometry program DISMAN, and the structures resulting from 181 converged calculations were energy refined with the program FANTOM. A group of 120 conformers was selected on the basis of the residual constraint violations and energy criteria to represent the solution structure. The average of the pairwise root-mean-square distances calculated for the backbone atoms of the 120 structures was 0.58 {angstrom}. The structure represents a novel conformation of cyclosporin A, for which the backbone conformation is significantly different from the previously reported structures in single crystals and in chloroform solution. The structure has all peptide bonds in the trans form, contains no elements of regular secondary structure and no intramolecular hydrogen bonds, and exposes nearly all polar groups to its environment. The root-mean-square distance between the backbone atoms of the crystal structure of cyclosporin Amore » and the mean of the 120 conformers representing the NMR structure of cyclosporin A bound to cyclophilin is 2.5 {angstrom}.« less

Authors:
; ; ; ;  [1]; ;  [2]
  1. (Eidgenoessische Technische Hochschule-Hoenggerberg, Zuerich (Switzerland))
  2. (Sandoz Pharma AG, Basel (Switzerland))
Publication Date:
OSTI Identifier:
5032348
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemistry; (United States); Journal Volume: 30:26
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; IMMUNOSUPPRESSIVE DRUGS; NUCLEAR MAGNETIC RESONANCE; AQUEOUS SOLUTIONS; D CODES; F CODES; GEOMETRY; MOLECULAR STRUCTURE; OVERHAUSER EFFECT; COMPUTER CODES; DISPERSIONS; DRUGS; MAGNETIC RESONANCE; MATHEMATICS; MIXTURES; RESONANCE; SOLUTIONS; 550201* - Biochemistry- Tracer Techniques

Citation Formats

Weber, C., Wilder, G., von Freyberg, B., Braun, W., Wuethrich, K., Traber, R., and Widmer, H.. The NMR structure of cyclosporin A bound to cyclophilin in aqueous solution. United States: N. p., 1991. Web. doi:10.1021/bi00240a029.
Weber, C., Wilder, G., von Freyberg, B., Braun, W., Wuethrich, K., Traber, R., & Widmer, H.. The NMR structure of cyclosporin A bound to cyclophilin in aqueous solution. United States. doi:10.1021/bi00240a029.
Weber, C., Wilder, G., von Freyberg, B., Braun, W., Wuethrich, K., Traber, R., and Widmer, H.. 1991. "The NMR structure of cyclosporin A bound to cyclophilin in aqueous solution". United States. doi:10.1021/bi00240a029.
@article{osti_5032348,
title = {The NMR structure of cyclosporin A bound to cyclophilin in aqueous solution},
author = {Weber, C. and Wilder, G. and von Freyberg, B. and Braun, W. and Wuethrich, K. and Traber, R. and Widmer, H.},
abstractNote = {Cyclosporin A bound to the presumed receptor protein cyclophilin was studied in aqueous solution at pH 6.0 by nuclear magnetic resonance spectroscopy using uniform {sup 15}N- or {sup 13}C-labeling of cyclosporin A and heteronuclear spectral editing techniques. With an input of 108 intramolecular NOEs and four vicinal {sup 3}J{sub HN{alpha}} coupling constants, the three-dimensional structure of cyclosporin A bound to cyclophilin was calculated with the distance geometry program DISMAN, and the structures resulting from 181 converged calculations were energy refined with the program FANTOM. A group of 120 conformers was selected on the basis of the residual constraint violations and energy criteria to represent the solution structure. The average of the pairwise root-mean-square distances calculated for the backbone atoms of the 120 structures was 0.58 {angstrom}. The structure represents a novel conformation of cyclosporin A, for which the backbone conformation is significantly different from the previously reported structures in single crystals and in chloroform solution. The structure has all peptide bonds in the trans form, contains no elements of regular secondary structure and no intramolecular hydrogen bonds, and exposes nearly all polar groups to its environment. The root-mean-square distance between the backbone atoms of the crystal structure of cyclosporin A and the mean of the 120 conformers representing the NMR structure of cyclosporin A bound to cyclophilin is 2.5 {angstrom}.},
doi = {10.1021/bi00240a029},
journal = {Biochemistry; (United States)},
number = ,
volume = 30:26,
place = {United States},
year = 1991,
month = 7
}
  • Cyclosporin A (CsA), a potent immunosuppressant, is known to bind with high specificity to cyclophilin (CyP), a 17.7 kDa protein with peptidyl-prolyl isomerase activity. In order to investigate the three-dimensional structure of the CsA/CyP complex, the authors have applied a variety of multidimensional NMR methods in the study of uniformly {sup 13}C-labeled CsA bound to cyclophilin. The {sup 1}H and {sup 13}C NMR signals of cyclosporin A in the bound state have been assigned, and, from a quantitative interpretation of the 3D NOE data, the bound conformation of CsA has been determined. Three-dimensional structures of CsA calculated from the NOEmore » data by using a distance geometry/simulated annealing protocol were found to be very different form previously determined crystalline and solution conformations of uncomplexed CsA. In addition, from CsA/CyP NOEs, the portions of CsA that interact with cyclophilin were identified. For the most part, those CsA residues with NOEs to cyclophilin were the same residues important for cyclophilin binding and immunosuppressive activity as determined from sturcture/activity relationships. The structural information derived in this study together with the known structure/activity relationships for CsA analogues may prove useful in the design of improved immunosuppressants. Moreover, the approach that is described for obtaining the structural information is widely applicable to the study of small molecule/large molecule interactions.« less
  • No abstract prepared.
  • No abstract prepared.
  • The CD147 receptor plays an integral role in numerous diseases by stimulating the expression of several protein families and serving as the receptor for extracellular cyclophilins, however, neither CD147 nor its interactions with its cyclophilin ligands have been well characterized in solution. CD147 is a unique protein in that it can function both at the cell membrane and after being released from cells where it continues to retain activity. Thus, the CD147 receptor functions through at least two mechanisms that include both cyclophilin-independent and cyclophilin-dependent modes of action. In regard to CD147 cyclophilin-independent activity, CD147 homophilic interactions are thought tomore » underlie its activity. In regard to CD147 cyclophilin-dependent activity, cyclophilin/CD147 interactions may represent a novel means of signaling since cyclophilins are also peptidyl-prolyl isomerases.« less
  • Cyclophilin 40 is a recently identified member of the cyclophilin family that is found in an unactivated steroid hormone receptor complex. Cyclophilin 40 possesses a region homologous to FKBP59, a member of the FK506-binding protein family that is also a component of the receptor complex. We report the isolation and sequencing of the entire human cyclophilin 40 (hCyP40) gene (human gene symbol PPID). The gene contains 10 exons (43 to 698 bp) and 9 introns encompassing 14.2 kb. The exon organization of the cyclophilin-like region is not similar to that of the human cyclophilin A gene (PPIA), suggesting their earlymore » divergence in evolution. Determination of the sequence of the 5{prime} end of the hCyP40 mRNA by an {open_quotes}anchor-ligation PCR{close_quotes} procedure showed that transcription is initiated from a cluster of sites about 80 bp upstream from the first in-frame ATG. The immediate 5{prime}-flanking region of the gene lacks typical TATA and CAAT boxes, but is GC-rich and contains Sp1 sites, features characteristic of promoters associated with housekeeping genes. The hCyP40 gene was mapped to chromosome 4 by PCR with genomic DNA from somatic cell hybrids. As shown by {open_quotes}Zoo blot{close_quotes} analysis, the cylophilin 40 gene appears to be highly conserved throughout evolution. 47 refs., 4 figs., 1 tab.« less