Synthesis of Streptococcus pneumoniae type 3 neoglycoproteins varying in oligosaccharide chain length, loading and carrier protein.
The preparation is described of a range of neoglycoproteins containing synthesised fragments of the capsular polysaccharide of Streptococcus pneumoniae type 3, that is beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->O)-(CH2)3NH2 (1), beta-D-Glcp-(1-->3)-beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->O)-(CH2)3NH2 (2), and beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->3)-beta-D-GlcpA-(1-->4)-beta-D-Glcp-(1-->O)-(CH4)NH2 (3). A blockwise approach was developed for the synthesis of the protected carbohydrate chains, in which the carboxylic groups were introduced prior to deprotection by selective oxidation of HO-6 in the presence of HO-4 by using TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy radical). After deprotection, the 3-aminopropyl spacer of the fragments was elongated with diethyl squarate (3,4-diethoxy-3-cyclobutene-1,2-dione) and the elongated oligosaccharides were conjugated to CRM197 (cross-reacting material of diphtheria toxin), KLH (keyhole limpet hemocyanin) or TT (tetanus toxoid). The resulting neoglycoconjugates varied in oligosaccharide chain length, oligosaccharide loading and protein carrier. These well-defined conjugates are ideal probes for evaluating the influence of the different structural parameters in immunological tests.
Lefeber
D J
DJ
Bijvoet Center, Department of Bio-Organic Chemistry Utrecht University, The Netherlands.
Kamerling
J P
JP
Vliegenthart
J F
JF
D000276:Adjuvants, Immunologic / Q000737:chemistry; D016667:Bacterial Capsules; D001426:Bacterial Proteins / Q000737:chemistry; D002352:Carrier Proteins / Q000737:chemistry; D006023:Glycoproteins / Q000138:chemical synthesis*; D006433:Hemocyanins / Q000737:chemistry; D009844:Oligosaccharides / Q000138:chemical synthesis / Q000737:chemistry; D022242:Pneumococcal Vaccines / Q000138:chemical synthesis*; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000276:immunology; D013296:Streptococcus pneumoniae / Q000737:chemistry*; D013745:Tetanus Toxoid / Q000737:chemistry
D000276:Adjuvants, Immunologic; D001426:Bacterial Proteins; D002352:Carrier Proteins; D006023:Glycoproteins; D009844:Oligosaccharides; D022242:Pneumococcal Vaccines; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid; C116872:capsular polysaccharide 33F; C028581:CRM197 (non-toxic variant of diphtheria toxin); D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin