Synthesis of fluorescent glycosphingolipids and neoglycoconjugates which contain 6-gala oligosaccharides using the transglycosylation reaction of a novel endoglycoceramidase (EGALC).
Endoglycoceramidase is a glycohydrolase capable of hydrolysing the O-glycosidic linkage between oligosaccharides and ceramides of various glycosphingolipids. However, no endoglycoceramidase reported so far can hydrolyse 6-gala series glycosphingolipids which possess the common structure R-Gal beta1-6Gal beta1-1'Cer. Recently, we found a novel endoglycoceramidase (endogalactosylceramidase, EGALC) which specifically hydrolyses 6-gala series glycosphingolipids. Here, we report that EGALC catalyses the hydrolysis as well as transglycosylation. An intact sugar chain of neogalatriaosylceramide (Gal beta1-6Gal beta1-6Gal beta1-1'Cer) was found to be transferred by EGALC to a primary hydroxyl group of various alkanols and non-ionic detergents such as Triton X-100 generating corresponding alkyl- and Triton-trigalactooligosaccharides. Furthermore, fluorescent 6-gala series glycosphingolipids were synthesized by transglycosylation in a reaction with EGALC using fluorescent ceramides as acceptors. Because of high efficiency and broad acceptor specificity, EGALC would facilitate the synthesis of fluorescent glycosphingolipids and neoglycoconjugates which contain 6-gala oligosaccharides.
Ishibashi
Yohei
Y
Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
Kiyohara
Masashi
M
Okino
Nozomu
N
Ito
Makoto
M
D002240:Carbohydrate Sequence; D005453:Fluorescence; D005699:Galactosylceramides / Q000737:chemistry*; D006026:Glycoside Hydrolases / Q000378:metabolism*; D006028:Glycosphingolipids / Q000096:biosynthesis* / Q000737:chemistry*; D006031:Glycosylation; D006878:Hydroxides / Q000737:chemistry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014281:Trihexosylceramides / Q000737:chemistry*
D005699:Galactosylceramides; D006028:Glycosphingolipids; D006878:Hydroxides; D009844:Oligosaccharides; D014281:Trihexosylceramides; C526065:neogalatriaosylceramide; C031356:hydroxide ion; D006026:Glycoside Hydrolases; C050427:endoglycoceramidase