Multifunctionality of Campylobacter jejuni sialyltransferase CstII: characterization of GD3/GT3 oligosaccharide synthase, GD3 oligosaccharide sialidase, and trans-sialidase activities.
CstII from bacterium Campylobacter jejuni strain OH4384 has been previously characterized as a bifunctional sialyltransferase having both alpha2,3-sialyltransferase (GM3 oligosaccharide synthase) and alpha2,8-sialyltransferase (GD3 oligosaccharide synthase) activities which catalyze the transfer of N-acetylneuraminic acid (Neu5Ac) from cytidine 5'-monophosphate (CMP)-Neu5Ac to C-3' of the galactose in lactose and to C-8 of the Neu5Ac in 3'-sialyllactose, respectively (Gilbert M, Karwaski MF, Bernatchez S, Young NM, Taboada E, Michniewicz J, Cunningham AM, Wakarchuk WW. 2002. The genetic bases for the variation in the lipo-oligosaccharide of the mucosal pathogen, Campylobacter jejuni. Biosynthesis of sialylated ganglioside mimics in the core oligosaccharide. J Biol Chem. 277:327-337). We report here the characterization of a truncated CstII mutant (CstIIDelta32(I53S)) cloned from a synthetic gene whose codons are optimized for an Escherichia coli expression system. In addition to the alpha2,3- and alpha2,8-sialyltransferase activities reported before for the synthesis of GM3- and GD3-type oligosaccharides, respectively, the CstIIDelta32(I53S) has alpha2,8-sialyltransferase (GT3 oligosaccharide synthase) activity for the synthesis of GT3 oligosaccharide. It also has alpha2,8-sialidase (GD3 oligosaccharide sialidase) activity that catalyzes the specific cleavage of the alpha2,8-sialyl linkage of GD3-type oligosaccharides and alpha2,8-trans-sialidase (GD3 oligosaccharide trans-sialidase) activity that catalyzes the transfer of a sialic acid from a GD3 oligosaccharide to a different GM3 oligosaccharide (3'-sialyllactoside). The donor substrate specificity study of the CstIIDelta32(I53S) GD3 oligosaccharide synthase activity indicates that the enzyme is flexible in using different CMP-activated sialic acids and their analogs for the synthesis of GD3 oligosaccharides containing natural and nonnatural modifications at the terminal sialic acid.
Cheng
Jiansong
J
Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616, USA.
Yu
Hai
H
Lau
Kam
K
Huang
Shengshu
S
Chokhawala
Harshal A
HA
Li
Yanhong
Y
Tiwari
Vinod Kumar
VK
Chen
Xi
X
D000595:Amino Acid Sequence; D001483:Base Sequence; D016123:Campylobacter jejuni / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D005732:Gangliosides / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D007700:Kinetics; D007790:Lactosylceramides / Q000378:metabolism; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000378:metabolism*; D012799:Sialyltransferases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D013379:Substrate Specificity
D005732:Gangliosides; D006023:Glycoproteins; D007790:Lactosylceramides; C026226:ganglioside, GD3; C047989:trisialosyllactosylceramide; D012799:Sialyltransferases; C043662:alpha-N-acetylneuraminate alpha-2,8-sialyltransferase; C069715:trans-sialidase; D009439:Neuraminidase