Assignment of the protonated 13C resonances of apo-neocarzinostatin by 2D heteronucle
 

Assignment of the protonated 13C resonances of apo-neocarzinostatin by 2D heteronuclear NMR spectroscopy at natural abundance.

Related Articles Assignment of the protonated 13C resonances of apo-neocarzinostatin by 2D heteronuclear NMR spectroscopy at natural abundance.

J Biomol NMR. 1994 Sep;4(5):689-702

Authors: Lefevre C, Adjadj E, Quiniou E, Mispelter J

Nearly complete assignment of the protonated carbon resonances of apo-neocarzinostatin, a 113-amino acid antitumor antibiotic carrier protein, has been achieved at natural 13C abundance using heteronuclear 2D experiments. Most of the cross peaks in the proton-carbon correlation map were identified by the combined use of HMQC, HMQC-RELAY and HMQC-NOESY spectra, using already published proton chemical shifts. However, double-DEPT and triple-quantum experiments had to be performed for the edition of CH and CH2 side-chain groups, respectively, which were hardly visible on HMQC-type maps. The triple-quantum pulse sequence was adapted from its original scheme to be applicable to a natural abundance sample. The correlation between carbon chemical shifts and the apo-neocarzinostatin structure is discussed. In particular, 13C alpha secondary shifts correlate well with the backbone conformation. These shifts also yield information about the main-chain flexibility of the protein. Assignments reported herein will be used further for interpretation of carbon relaxation times in a study of the internal dynamics of apo-neocarzinostatin.

PMID: 7919954 [PubMed - indexed for MEDLINE]



Source: PubMed