I. Mononen et al., ENZYMATIC-SYNTHESIS OF THE N-GLYCOSIDIC BOND BY BETA-ASPARTYLATION OFGLYCOSYLAMINES, Biochemical and biophysical research communications, 218(2), 1996, pp. 510-513
Glycosylasparaginase (EC 3.5.1.26) is an amidase, which cleaves the N-
glycosidic linkage during glycoprotein degradation leading to the libe
ration of L-aspartic acid from various glycoasparagines. In this work
we demonstrate that glycosylasparaginase is also capable of catalyzing
the synthesis of the N-glycosidic bond by N-beta-aspartylation of bet
a-glycosylamine using 1-amino-N-acetylglucosamine as the nucleophile a
nd L-aspartic acid beta-methyl ester as the beta-aspartyl donor. Kinet
ic studies indicated that beta-glycosylamine has 1390-fold higher reac
tivity than water in the de-beta-aspartylation of the beta-aspartylenz
pme, indicative of the presence of a beta-glycosylamine binding sub-si
te at the substrate binding site of glycosylasparaginase. The reaction
can be applied to glycosylasparaginase-catalyzed biosynthesis of nove
l glycoasparagines. (C) 1996 Academic Press, Inc.