Evaluation of the effect of glycosylation on the enzymic hydrolysis of peptides

The glycosylated building block N-alpha-(fluoren-9-ylmethoxycarbonyl)-N-gamma-[2,3,6-tri-O-acetyl-4-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-beta-D-glucopyranosyl]-L-asparagine pentafluorophenyl ester 7 has been synthesized and incorporated into the solid-phase synthesis of a panel of peptides and N-linked glycopeptides. These have been synthesized as internally quenched fluorogenic compounds where the position of the glycosylated asparagine residue is sequentially varied. Enzymic hydrolysis of these substrates with Savinase has been followed by fluorescence and the k(cat)/K-M-values have been obtained. It is observed that the glycopeptides are less susceptible to proteolytic degradation than are the corresponding peptides.