Measurement of amide proton exchange rates and NOEs with water in 13C/15N-enriched calcineurin B

J Biomol NMR. 1993 Nov;3(6):627-38. doi: 10.1007/BF00198368.

Abstract

A rapid and sensitive 2D approach is presented for measuring amide proton exchange rates and the NOE interaction between amide protons and water. The approach is applicable to uniformly 13C/15N-enriched proteins and can measure magnetization exchange rates in the 0.02 to > 20 s-1 range. The experiments rely on selective excitation of the water resonance, coupled with purging of underlying H alpha resonances, followed by NOESY- or ROESY-type transfer to amide protons, which are dispersed by the amide 15N frequencies in an HSQC-type experiment. Two separate but interleaved experiments, with and without selective inversion of the H2O resonance, yield quantitative results. The method is demonstrated for a sample of the calcium-binding protein calcineurin B. Results indicate rapid amide exchange for the five calcineurin B residues that are analogous to the five rapidly exchanging residues in the 'central helix' of the homologous protein calmodulin.

Publication types

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

MeSH terms

  • Amides / chemistry*
  • Calcineurin
  • Calmodulin-Binding Proteins / chemistry*
  • Carbon Isotopes
  • Magnetic Resonance Spectroscopy
  • Nitrogen Isotopes
  • Phosphoprotein Phosphatases / chemistry*
  • Protons
  • Water

Substances

  • Amides
  • Calmodulin-Binding Proteins
  • Carbon Isotopes
  • Nitrogen Isotopes
  • Protons
  • Water
  • Calcineurin
  • Phosphoprotein Phosphatases