Glycopeptide synthesis through endo-glycosidase-catalyzed oligosaccharide transfer of sugar oxazolines: probing substrate structural requirement.
An array of sugar oxazolines was synthesized and tested as donor substrates for the Arthrobacter endo-beta-N-acetylglucosaminidase (Endo-A)-catalyzed glycopeptide synthesis. The experiments revealed that the minimum structure of the donor substrate required for Endo-A catalyzed transglycosylation is a Man beta1-->4-GlcNAc oxazoline moiety. Replacement of the beta-D-Man moiety with beta-D-Glc, beta-D-Gal, and beta-D-GlcNAc monosaccharides resulted in the loss of substrate activity for the disaccharide oxazoline. Despite this, the enzyme could tolerate modifications such as attachment of additional sugar residues or a functional group at the 3- and/or 6-positions of the beta-D-Man moiety, thus allowing a successful transfer of selectively modified oligosaccharides to the peptide acceptor. On the other hand, the enzyme has a great flexibility for the acceptor portion and could take both small and large GlcNAc-peptides as the acceptor. The studies implicate a great potential of the endoglycosidase-catalyzed transglycosylation for constructing both natural and selectively modified glycopeptides.
Zeng
Ying
Y
Institute of Human Virology, University of Maryland Biotechnology Institute, University of Maryland, Baltimore, MD 21201, USA.
Wang
Jingsong
J
Li
Bing
B
Hauser
Steven
S
Li
Hengguang
H
Wang
Lai-Xi
LX
D000595:Amino Acid Sequence; D001173:Arthrobacter / Q000201:enzymology; D002240:Carbohydrate Sequence; D002384:Catalysis; D006020:Glycopeptides / Q000096:biosynthesis* / Q000737:chemistry; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000502:physiology*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D010080:Oxazoles / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity
D006020:Glycopeptides; D009844:Oligosaccharides; D010080:Oxazoles; D006026:Glycoside Hydrolases