Abstract
We developed a modified method enabling stable MALDI-MS analysis and fluorescent detection of sialyl-compounds. The modification involved the amidation of sialic acid (Neu5Ac) at the position of the carboxyl group using the fluorescent reagent, 2-(2-pyridilamino)ethylamine (PAEA). In this study the following sialyl-compounds were amidated, 3′-sialyllactose (3′-SL), 6′-sialyllactose (6′-SL), and ganglioside GM3. Yields of PAEA-3′-SL, PAEA-6′-SL, and PAEA-GM3 were 45%, 60%, and 30%, respectively. The PAEA-amidation enabled fluorescence detection of structural isomers using HPLC and TLC at sensitivity levels as low as pmol. In MALDI-TOF-MS and/or MS/MS analysis in positive ion mode, PAEA-amidation provided the following advantages: suppression of preferential cleavage of Neu5Ac; enhancement of molecular-related ion intensities; simplification of MS spectra; and finally, since PAEA-amidation did not cleave the linkage between sugar and aglycon of sialylglycoconjugate, MALDI-TOF-MS and MS/MS analyses revealed the complete structure of the molecule.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
