03043nas a2200397   4500000000100000008004100001260001600042653002400058653002200082653003000104653002600134653002300160653001400183653004000197653001600237653001800253653001800271653001200289653002800301653002400329653002100353653002500374653002000399653001900419100001700438700001200455700001400467700001600481700001500497700001600512245013900528300001100667490000800678520194500686022001402631       1988                            d  c1988 Dec 0110aAntigens, Bacterial10aBlotting, Western10aCarbohydrate Conformation10aCarbohydrate Sequence10aChemical Phenomena10aChemistry10aElectrophoresis, Polyacrylamide Gel10aGlycolipids10aGlycoproteins10aGlycosylation10aleprosy10aMolecular Sequence Data10aMolecular Structure10aMolecular Weight10aMycobacterium leprae10aSerologic Tests10aTrisaccharides1 aChatterjee D1 aCho S N1 aStewart C1 aDouglas J T1 aFujiwara T1 aBrennan P J00aSynthesis and immunoreactivity of neoglycoproteins containing the trisaccharide unit of phenolic glycolipid I of Mycobacterium leprae.  a241-600 v1833 a<p>The trisaccharide segment, O-(3,6-di-O-methyl-beta-D-glucopyranosyl)-(1----4)-O-(2,3-di-O-methyl- alpha-L-rhamnopyranosyl)-(1----2)-3-O-methyl-L-rhamnopyranose, of the Mycobacterium leprae-specific phenolic glycolipid I has been synthesized as its 8-(methoxycarbonyl)octyl glycoside and coupled to a carrier protein, to produce a leprosy-specific neoglycoprotein, the so-called natural trisaccharide-octyl-bovine serum albumin (NT-O-BSA). Special features of the synthetic strategy were the use of silver trifluoromethanesulfonate (triflate) to promote glycosylation, resulting in the rhamnobiose in high yield and absolute stereospecificity. The terminal 3,6-di-O-methyl-D-glucopyranosyl group was introduced after O-deallylation of the rhamnobiose. Removal of protecting groups yielded the trisaccharide hapten suitable for coupling to carrier protein. Poly(acrylamide)-gel electrophoresis of the neoglycoprotein demonstrated its purity, and subsequent immunoblotting with a monoclonal antibody directed to the terminal 3,6-di-O-methyl-beta-D-glucopyranosyl epitope of the native glycolipid demonstrated its antigenicity. Comparative serological testing in enzyme-linked immunosorbent assays of NT-O-BSA, the corresponding disaccharide-containing products, and another trisaccharide-containing neoglycoprotein, O-(3,6-di-O-methyl-beta-D-glucopyranosyl)-(1----4)-O-(2,3-di-O- methyl-alpha-L-rhamnopyranosyl)-(1----2)-(3-O-methyl-alpha-L-rhamnopy ran osyl)- (1----4')-oxy-(3-phenylpropanoyl)-BSA (NT-P-BSA) [Fujiwara et al., Agric. Biol. Chem., 51 (1987) 2539-2547] against sera from leprosy patients and control populations showed concordance; the presence of the innermost sugar did not contribute significantly to sensitivity or specificity. The di- and tri-saccharide-containing neoantigens, on account of ready availability and solubility, provide greater flexibility than the native glycolipid for the serodiagnosis of leprosy.</p>  a0008-6215