Measurement of amide proton exchange rates and NOEs with water in13C/15N-enriched calcineurin B

✍ Scribed by Stephan Grzesiek; Ad Bax

• Book ID: 104660130
• Publisher: Springer Netherlands
• Year: 1993
• Tongue: English
• Weight: 696 KB
• Volume: 3
• Category: Article
• ISSN: 0925-2738
• DOI: 10.1007/bf00198368

✦ Synopsis

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 L3C/~SN-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 a resonances, followed by NOESY-or ROESY-type transfer to amide protons, which are dispersed by the amide ~SN frequencies in an HSQC-type experiment. Two separate but interleaved experiments, with and without selective inversion of the H20 resonance, yield quantitative results. The method is demonstrated for a sample of the calciumbinding 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 calmodutin.