Title : Rapid and simple approach for the NMR resonance assignment of
the carbohydrate chains of an intact
glycoprotein
Abstract :
- Application of gradient-enhanced natural abundance 1H-13C HSQC and HSQC-TOCSY to the alpha-subunit of human chorionic gonadotropin
- The structure assessment of an intact glycoprotein in solution requires an extensive assignment of the carbohydrate NMR resonances
- However, assignment of homonuclear spectra is very complicated because of the severe overlap of protein and carbohydrate signals
- Application of pulsed field gradients allowed high quality natural abundance 1H-13C HSQC and HSQC-TOCSY spectra to be recorded of the alpha-subunit of human chorionic gonadotropin
- Most carbohydrate 1H-13C correlations appear in a distinct region between the aromatic region and the protein C alpha-H alpha region
- The enormous reduction in overlap led to fast and unambiguous assignment of the anomeric 1H-13C correlations
- Subsequently, correlations of the monosaccharide skeleton atoms were readily assigned in the HSQC-TOCSY spectrum