Multivalent sialylation of β-thio- glycoclusters by Trypanosoma cruzi trans sialidase and analysis by high performance anion exchange chromatography

ALEJANDRO J. CAGNONI; MARÍA LAURA UHRIG; AGUSTI, ROSALÍA; JOSÉ KOVENSKY; CANO, MARÍA EMILIA; LEDERKREMER, ROSA

GLYCOCONJUGATE JOURNAL

SPRINGER

Lugar: Berlin; Año: 2016

0282-0080

The synthesis of multivalent sialylated glycoclustersis herein addressed by a chemoenzymatic approach using thetrans-sialidase of Trypanosoma cruzi (TcTS). Multivalent β-thio-galactopyranosides and β-thio-lactosides were used as ac-ceptor substrates and 3′-sialyllactose as the sialic acid donor.High performance anion exchange chromatography withpulsed amperometric detection (HPAEC-PAD) was shown tobe an excellent technique for the analysis of the reactionproducts. Different eluting conditions were optimized toallow the simultaneous resolution of the sialylated species,as well as their neutral precursors. The TcTS efficientlytransferred sialyl residues to di, tri, tetra and octa β-thiogalactosides. In the case of an octavalent thiolactoside,up to six polysialylated compounds could be resolved.Preparative sialylation reactions were performed using thetetravalent and octavalent acceptor substrates. The mainsialylated derivatives could be unequivocally assigned byMALDI mass spectrometry. Inhibition of the transfer tothe natural substrate, N-acetyllactosamine, was also studied. The octalactoside caused 82 % inhibition of sialic acidtransfer when we used equimolar concentrations of donor,acceptor and inhibitor.