AN HNCO-BASED PULSE SCHEME FOR THE MEASUREMENT OF C-13(ALPHA)-H-1(ALPHA) ONE-BOND DIPOLAR COUPLINGS IN N-15, C-13 LABELED PROTEINS

A triple resonance pulse scheme is presented for recording 13C(alpha)- H-1(alpha) one-bond dipolar couplings in N-15, C-13 labeled proteins. HNCO correlation maps are generated where the carbonyl chemical shift is modulated by the C-13(alpha)-H-1(alpha) coupling, With the two doub let components separated into individual data sets. The experiment mak es use of recently described methodology whereby the protein of intere st is dissolved in a dilute solution of bicelles which orient above a critical temperature, thus permitting measurement of significant coupl ings (Tjandra and Bar, 1997a). An application to the protein ubiquitin is described.