Characterization of β-1,2-Mannosyltransferase in Candida guilliermondii and Its Utilization in the Synthesis of Novel Oligosaccharides

• Published in: The Journal of biological chemistry 1997-07, Vol.272 (27), p.16822
• Main Authors: Akifumi Suzuki, Nobuyuki Shibata, Mikiko Suzuki, Fumie Saitoh, Hiroko Oyamada, Hidemitsu Kobayashi, Shigeo Suzuki, Yoshio Okawa
• Format: Article
• Language: English
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.272.27.16822

A particulate insoluble enzyme fraction containing mannosyltransferases from Candida guilliermondii IFO 10279 strain cells was obtained as the residue after extracting a 105,000 × g pellet of cell homogenate with 1% Triton X-100. Incubation of this fraction with a mannopentaose, Manα1→3(Manα1→6)Manα1→2Manα1→2Man, in the presence of GDP-mannose and Mn 2+ ion at pH 6.0 gave a third type of β-1,2 linkage-containing mannohexaose, Manβ1→2Manα1→3(Manα1→6)Manα1→2Manα1→2Man, the structure of which was identified by means of a sequential NMR assignment. The results of a substrate specificity study indicated that the β-1,2-mannosyltransferase requires a mannobiosyl unit, Manα1→ 3Manα1→, at the nonreducing terminal site. We synthesized novel oligosaccharides using substrates possessing a nonreducing terminal α-1,3-linked mannose unit prepared from various yeast mannans. Further incubation of the enzymatically synthesized oligosaccharide with the enzyme fraction gave the following structure, Manβ1→2Manβ1→2Manα1→3(Manα1→6)Manα1→ 2Manα1→2Man, which has been found to correspond to antigenic factor 9. Incubation of Candida albicans serotype B mannan with the enzyme fraction gave significantly transformed mannan, which contains the third type of β-1,2-linked mannose units.