The Section works on elucidating the interaction of (complex) carbohydrate immuno-determinants with monoclonal antibodies (MAbs). We are executing: 1. Physico-chemical studies on antibody/antigen systems (V. cholera). 2. The synthesis of immunodeterminants of pathogenic entero-bacteria for affinity studies, so as to evaluate procedures for conjugate- vaccine development. 3. The amino acid sequencing by cDNA technique of monoclonal immunoglobulins obtained against V. cholera., so as to elucidate their antigen-binding phenomena. Specifically, we have synthesized the methyl a-glycoside of the trisaccharide fragment of the V. Cholera Inaba series, and mono through tetrasaccharides in the V. Cholera Ogawa series. Having prepared the crystalline monosaccharide fragments representing the terminus of the O-PS of both the Ogawa and the Inaba series we were able to show that these two compounds have differing structures. In pursuing the preparation of neoglycoprotein-based immunogens for production of anti-cholera antibodies, we have synthesized a hexasaccharide fragment of the O-PS, functionalized for attachement to a protein carrier. Circular dichroism of the O-specific polysaccharide of Vibrio cholerae O1 and some related derivatives has been investigated. The study confirmed the relationship of synthetic models to the natural O-PS. The amino acid sequence of some anti S. dysenteriae type 1 antibodies have been determined by cDNA cloning. There appears to be a remarkable diversity in sequence amongst these antibodies, even when directed against the same immunogen. A detailed study has shown that thermodynamic parameters can describe the differing binding patterns (""""""""groove"""""""" versus """"""""cavity"""""""") that different antibodies show against the same antigen.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Intramural Research (Z01)
Project #
1Z01DK059701-23
Application #
2573689
Study Section
Special Emphasis Panel (LMC)
Project Start
Project End
Budget Start
Budget End
Support Year
23
Fiscal Year
1996
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code
Hou, Shu-jie; Kovac, Pavol (2010) Enhanced stereoselectivity of alpha-mannosylation under thermodynamic control using trichloroacetimidates. Carbohydr Res 345:999-1007
Hou, Shu-Jie; Saksena, Rina; Kovac, Pavol (2008) Preparation of glycoconjugates by dialkyl squarate chemistry revisited. Carbohydr Res 343:196-210
Saksena, Rina; Adamo, Roberto; Kovac, Pavol (2007) Immunogens related to the synthetic tetrasaccharide side chain of the Bacillus anthracis exosporium. Bioorg Med Chem 15:4283-310
Wang, Denong; Carroll, Gregory T; Turro, Nicholas J et al. (2007) Photogenerated glycan arrays identify immunogenic sugar moieties of Bacillus anthracis exosporium. Proteomics 7:180-4
Provenzano, Daniele; Kovac, Pavol; Wade, William F (2006) The ABCs (Antibody, B cells, and Carbohydrate epitopes) of cholera immunity: considerations for an improved vaccine. Microbiol Immunol 50:899-927
Ruttens, Bart; Kovac, Pavol (2006) Synthesis of spacer-equipped phosphorylated di-, tri- and tetrasaccharide fragments of the O-specific polysaccharide of Vibrio cholerae O139. Carbohydr Res 341:1077-80
Saksena, Rina; Adamo, Roberto; Kovac, Pavol (2006) Synthesis of the tetrasaccharide side chain of the major glycoprotein of the Bacillus anthracis exosporium. Bioorg Med Chem Lett 16:615-7
Wade, Terri K; Saksena, Rina; Shiloach, Joseph et al. (2006) Immunogenicity of synthetic saccharide fragments of Vibrio cholerae O1 (Ogawa and Inaba) bound to Exotoxin A. FEMS Immunol Med Microbiol 48:237-51
Kovacik, Vladimir; Bekesova, Slavka; Tvaroska, Igor et al. (2006) Positive electrospray ion trap multistage mass spectrometric fragmentation of synthetic analogs of saccharide part of lipopolysaccharides of Vibrio cholerae O:1. J Am Soc Mass Spectrom 17:749-56
Bekesova, Slavka; Kovacik, Vladimir; Chmelik, Josef et al. (2006) Negative electrospray, ion trap multistage mass spectrometry of synthetic fragments of the O-PS of Vibrio cholerae O:1. Eur J Mass Spectrom (Chichester, Eng) 12:43-50

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