Existence of Novel Branched Side Chains Containing β-1,2 and α-1,6 Linkages Corresponding to Antigenic Factor 9 in the Mannan of Candida guilliermondii

Shibata

Journal of Biological Chemistry

et al. 1997

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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, Man␣133(Man␣136)Man␣132Man␣132Man, in the presence of GDP-mannose and Mn 2؉ ion at pH 6.0 gave a third type of ␤-1,2 linkage-containing mannohexaose, Man␤132Man␣133(Man␣136)Man␣132Man-␣132Man, the structure of which was identified by means of a sequential NMR assignment. The results of a substrate specificity study indicated that the ␤-1,2-mannosyltransferase requires a mannobiosyl unit, Man␣13 3Man␣13, at the nonreducing terminal site. We synthesized novel oligosaccharides using substrates possessing a nonreducing terminal ␣-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, Man␤132Man␤132Man␣133(Man␣136)Man␣13 2Man␣132Man, 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 ␤-1,2-linked mannose units.

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 98%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

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

Shibata

Journal of Biological Chemistry

et al. 1997

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Presence of O‐glycosidically linked oligosaccharides in the cell wall mannan of Candida krusei purified with Benanomicin A

et al. 2018

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Cell wall mannan of the pathogenic yeast Candida krusei was prepared using the antibiotic Benanomicin A, which has a lectin‐like function. The chemical structure of this molecule was found to be similar to that of mannan prepared from the same yeast by the conventional method using Fehling reagent. Only a few degradation products were detected when the mannan prepared using Fehling reagent was subjected to alkali treatment (β‐elimination), but multiple α‐1,2‐linked oligosaccharides were detected when the mannan purified with Benanomicin A was treated with alkali. These results indicate that most of the O ‐linked sugar chains in mannan were lost under conventional conditions when exposed to the strongly alkaline Fehling reagent. In contrast, the O ‐glycosidic bond in mannan was not cleaved and the O ‐linked sugar chains were maintained and almost intact following treatment with the mild novel preparation method using Benanomicin A. Therefore, we argue that the new mannan preparation method using Benanomicin A is superior to conventional methods. In addition, our study suggests that some yeast mannans, whose overall structure has already been reported, may contain more O ‐linked sugar chains than previously recognized.

Concise and Effective Synthesis of 1→2 α‐Linked Mannopyranosyl Oligosaccharides and Related Antigenic Factor 34 and Dominant of Antigenic Factor 13

Zhu

Kong

2001

Chin. J. Chem.

the cell wall m n a n . 5-R Synthesis of 1-2 a-linked miinnose oligosaccharides has been achieved via multistep selective protection and deprotection using orthogonal masking groups. ' In continuation of our previous orthoester-based research'&'' here we report a new effective strategy for highly regio-and stereoselective synthesis of 1-2 a-linked mannopyranosyl oligosaccharides uk condensation of benzoylated manno-orthoesters .As outlined in Scheme 1, 2.3,4,6-tetra-O-acetyla-D-mannopposyl bromide ( 1) was transformed to the corresponding allyl orthoester in the presence of 2.4-11.1-tidine and allyl alcohol, and subsequent ZemplCn deacetylation ( 4 2 ) and benzoylation furnished the or-4 thoester 3. In the presence of catalytic amount of TMSOTf, 3 was transformed to allyl 2-0-acetyl-3,4,6-tri-O-benzoyI-a--mannopyranosyl-( I -+ 2 ) -3 , 4, 6-tri-0-benzoyl-a-D-mannopyranoside ( 4 ) in a good yield (66%) while the reamngement product allyl 2-0-acetyl-3,4,6-tri-0-benzoyl-a-D-mannopyranoside was the minor product ( 18% ) . l3 Formation of ( 1 -2 )-linked miinnose disaccharide from acetylated mannose orthoester was firstly reported by Lindhorst.14 However, the rather low yield ( < 30%) and difficulty for further transformation limited the use of this finding. We were gratified to find that replacement of the acetyl of the mannose orthoester with benzoyl made a substantially different result for the TMS promoted transformation of the mannose orthoester, i . e . the condensation product disaccharide 4 was obtained as the major product (66%).Owing to the high yield and easy separation, large quantity preparation of 4 was carried out and further transformation of 4 was successfully achieved. Thus deallylation followed by tri~hloroacetimidation~~ gave the disaccharide donor 5 (82%) while selective deacetylation16 at C-2 afforded acceptor 6 (93 % .