HN(alpha/beta-COCA-J) experiment for measurement of (1)J(C'C(alpha)) couplings from two-dimensional
Anew method for measurement of one-bond (13)C'-(13)C(alpha) scalar and dipolar couplings from a two-dimensional [(15)N, (1)H] correlation spectrum is presented. The experiment is based on multiple-quantum coherence, which is created between nitrogen and carbonyl carbon for simultaneous evolution of (15)N chemical shift and coupling between (13)C' and (13)C(alpha). Optional subspectral editing is provided by the spin-state-selective filters. The residual dipolar dipolar contribution to the (13)C'-(13)C(alpha) coupling can be measured from these simplified [(15)N, (1)H]-HSQC-like spectra. In this way, without explicit knowledge of carbon assignments, conformational changes of proteins dissolved in dilute liquid crystals can be probed conveniently, e.g., in structure activity relationship by NMR studies. The method is demonstrated with human cardiac troponin C. Copyright 1999 Academic Press.
Permi
P
Institute of Biotechnology, University of Helsinki, Helsinki, FIN-00014, Finland.
Sorsa
T
Kilpelainen
I
Annila
A