ABSTRACT
Glycopeptides with TN antigen (GalNAc)Ser/Thr and T-antigen structures (beta Gall-3GalNAc)Ser/Thr, described as tumor-associated antigens, were synthesized and coupled to bovine serum albumin. Alternatively, synthetic methods for the construction of beta-anomeric analogues of the TN and T-antigen glycopeptides were developed, aiming at antigenic structures having a varied stereochemistry of the linkage between the carbohydrate and the peptide moiety. As a further type of potential tumor-associated antigen, fucosyl-chitobiose asparagine glycopeptides were synthesized, deprotected, and coupled to bovine serum albumin. The chemical methods developed now make the complex sensitive glycoprotein partial structures accessible in analytically pure form and in preparative amounts.
Subject(s)
Antigens, Tumor-Associated, Carbohydrate/chemical synthesis , Disaccharides , Glycopeptides/immunology , Amino Acid Sequence , Antigens, Tumor-Associated, Carbohydrate/chemistry , Asparagine/chemistry , Carbohydrate Sequence , Fucose/chemistry , Glucans/chemistry , Glycopeptides/chemical synthesis , Glycopeptides/chemistry , Molecular Sequence Data , Molecular StructureABSTRACT
Glycopeptides with TN and T antigen structures that represent the N-terminal tripeptide of asialoglycophorin with blood-group M specificity have been synthesized using fluorenylmethoxycarbonyl (Fmoc) and 2-pyridylethoxycarbonyl (Pyoc) groups for amino protection and the benzyl ester as the carboxyl-blocking function. The Fmoc and the Pyoc groups could be removed by treatment with the weak base morpholine under conditions where the base-sensitive O-glycosyl-serine and -threonine linkages were stable. Ester groups were removed from the carbohydrate moieties with methanolic hydrazine, to give the TN and T antigen glycopeptides which were coupled to bovine serum albumin (BSA) via a carbodi-imide procedure and without any spacer groups. The resulting conjugates contained an average of greater than 20 glycopeptides per protein molecule. They are not microheterogeneous in the carbohydrate part as is commonly found for glycoproteins isolated from biological sources.
Subject(s)
Antigens, Neoplasm/chemical synthesis , Antigens, Tumor-Associated, Carbohydrate , Disaccharides/chemical synthesis , Glycopeptides/chemical synthesis , Base Sequence , Carbohydrate Sequence , Chemical Phenomena , Chemistry , Glycopeptides/immunology , Magnetic Resonance Spectroscopy , Methods , Molecular Sequence Data , Molecular Structure , Serum Albumin, BovineABSTRACT
A single-appointment technique to convert a solid obturator prosthesis into a hollow obturator prosthesis using available equipment and materials is described.
