O-Glycopeptides

Paulsen and associates (58) synthesized mono- and di-D-galactopyranosyl derivatives of L-serine/L-threonine. Condensation of the 2-azido-2-deoxy-glycosyl halides 61 and 62 with the benzyl or tert-butyl esters of iV-benzyl-oxycarbonyl (Z)-protected L-serine, L-threonine, and L-leucyl-L-serine (63 -65) in the presence of silver carbonate, silver perchlorate, Drierite, and molecular sieves gave (59) the corresponding O-glycopeptides 67-69. The free glycopeptides were obtained after total deprotection. 

Using the ethyl 1 -thio derivative (97) of 2,3,4-tri-O-benzoyl-D-xylose, the fully protected and free O-glycopeptides 99 and 100, having the TV-terminal amino acid sequence 3 to 6 (98) of the protein core of a proteodermatan sulfate have been prepared (69). 

Likewise, the galactosylation of O-glycopeptide derivatives 189-191 to give O-lactosamine - L-serine derivatives (192-194) using (1 - 4)-/ -d-... 

T.F. Herpin, W.B. Motherwell, J.M. Weibel, Two free radical routes for the preparation of novel difluoromethylene-linked serine-O-glycopeptide analogues, Chem. Commun. (1997) 923-924. 

O-Glycopeptides and glycoconjugates, in which the saccharide is linked to a peptide or a protein through a linear or a branched aliphatic spacer, have been used to enhance biological activity. 298 301 373,472,481-483 Peracetylated galabiose and lactose react with 3-sulfanylpropanoic acid in the presence of BF3 and the products have been used in the synthesis of HEL(46-61) and shorter fragments thereof. 164 ... 

B. Orthogonal deprotection of Fmoc O-glycopeptide tert-butyl... 

A. Orthogonal Deprotection of Fmoc O-glycopeptide Benzyl Esters... 

J. Martinez, A. A. Pavia, and E Wintemitz, Synthise d un O-glycopeptide par allongement de la chain peptidique da c8td N-termina] d un glycosylaminoacide, Carbohydr. Res. 50 148, (1976) and references cited therein. 

P. Schultheiss-Reimann and H. Kunz, O-Glycopeptide synthesis using 9-fluorenylmethoxycar-bonyl (Fmoc)-protected synthetic units, Angew. Chem. lnt. Ed. Engl. 22 62 (1983). 

N. P. Arbatsky, V. N. Shibaev, and N. K. Kochetkov, A new approach to localization of the O-glycosylation sites in glycoproteins Mass-spectrometric analysis of O-glycopeptides formed upon the reductive cleavage of the yeast mannoprotein by LiBH4-LiOH, Doklady Chem., 387 (2002) 328-331. 

Chemoenzymatic solution- and solid-phase synthesis of O-glycopeptides of the mucin domain of MAdCAM-1. A general route to O-LacNAc, O-sialyl-LacNAc, and O-sialyl-Lewis-X peptides, J. Am. Chem. Soc., 119 (1997) 8766-8776. 

Reimer, K., Meldal, M., Kusumoto, S., Fukase, K., and Bock, K. (1993) Small-scale solid-phase O-glycopeptide synthesis of linear and cyclized hexapeptides from blood-clotting factor IX containing 0-(a-D-Xyl-(l-3)-a-D-Xyl-(l-3)-(3-D-Glc)-L-Ser../. Am. Chem. Soc. Perkin Trans /., 925-932. 

Jensen, K., Hansen, P., Venugopal, D., and Barany, G. (1996) Synthesis of 2-acetamido-2-deoxy-(3-D-glucopyranose O-glycopeptides from V-dithiasuccinoyl -protected derivatives. /. Am. Chem. Soc. 118, 3148-3155. 

Kunz, H. and Birnbach, S. (1986) Synthesis of O-glycopeptides of the tumor-associated Tn- and T-antigen type and their binding to bovine serum albumin. Agnew. Chem Int Ed. 98(4), 360-362. 

Schultz, M. and Kunz, FI. (1993) Synthetic O-glycopeptides as model substrates for glycosyltransferases. Tetrahedron Asymmetry 4, 1205-1220. 

FIGURE 3.4 -Elimination of O-glycopeptides under alkaline conditions. 

Seitz O, Glycopeptide synthesis and the effects of glycosylation on protein structure and activity, Chembiochem, l(4) 214-46, 2000. 

Braun P, Waldmann H, Kunz H, Chemoenzymatic synthesis of O-glycopeptides carryng the tumor associated TN-antigen structure, Bioorg. Med. Chem., 1 197-207, 1993. 

Using the automated stepwise method of synthesis on a solid phase allows the synthesis of polypeptides consisting of up to 120 amino acids. The final polypeptide is purified by HLPC (high pressure liquid chromatography). O-glycopeptides are also constructed on a solid phase using DCC and N-hydroxybenzotriazole in DMF. ... 

Paulsen, H, Schultz, M, Klamann, J-D, Waller, B, Paal, M, Building units of oligosaccharides, LXVI. S3mthesis of O-glycopeptide blocks of glycophorine, Liebigs Arm. Chem., 2028-2048, 1985. 

Norberg, T, Liining, B, Tejbrant, J, Solid-pbase synthesis of O-glycopeptides, Methods Enzymol, 247, 87-106, 1994. 

Nakahara, Y, lijima, H, Ogawa, T, StereocontroUed approaches to O-glycopeptide synthesis. In Synthetic Oligosaccharides, Kovac, P, Ed., American Chemical Society, Washington DC, ACS Symp. Ser., Vol. 560, pp. 249-266, 1994. 

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