Hydrogen bonding geometry of a protein-bound carbohydrate from water exchange-mediated cross-relaxation

J Biomol NMR. 1998 Aug;12(2):209-22. doi: 10.1023/a:1008220522409.

Abstract

We present heteronuclear two-dimensional methods for the analysis of the geometry of exchangeable protons on a protein-bound carbohydrate. By using a water-selective NOESY-HSQC, we observed cross-relaxation between carbohydrate hydroxyl protons and non-exchangeable ring protons in the complex of [13C6]-alpha-methyl-D-mannopyranoside with recombinant rat mannose binding protein. Using a simple kinetic model, we were able to explain the differences in the initial slopes of the resulting cross-relaxation buildup curves in terms of the geometry of the hydroxyl protons in the bound state. The hydroxyl rotamers consistent with our cross-relaxation data fit very well with predictions based on the crystal structure of MBP bound to a mannose-rich oligosaccharide. These methods should be applicable to other systems where both ligand exchange and water exchange are fast relative to the rate of cross-relaxation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Carbohydrate Metabolism
  • Carbohydrates / chemistry*
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Escherichia coli / genetics
  • Hydrogen Bonding
  • In Vitro Techniques
  • Kinetics
  • Ligands
  • Magnetic Resonance Spectroscopy
  • Mannose-Binding Lectins
  • Methylmannosides / chemistry
  • Methylmannosides / metabolism
  • Models, Chemical
  • Oligosaccharides / chemistry
  • Oligosaccharides / metabolism
  • Protein Binding
  • Proteins / chemistry*
  • Proteins / metabolism
  • Rats
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Water / chemistry
  • Water / metabolism

Substances

  • Carbohydrates
  • Carrier Proteins
  • Ligands
  • Mannose-Binding Lectins
  • Methylmannosides
  • Oligosaccharides
  • Proteins
  • Recombinant Proteins
  • Water
  • methylmannoside