Our studies with purified fimbrial proteins have demonstrated an interaction with salivary-coated hydroxyapatite (sHAP) that involves the carboxyl third of the major 43 kDa fimbrillin subunit. In contrast, immunodominant regions appear to reside in the N-terminus of the fimbrillin subunit. The principal goal of this study is to further define the structure-function relationship of fimbriae and fimbrial-associated adhesins of P. gingivalis. Molecular genetic approaches to studying the fimbriae will be used to evaluate the genes specifying the P. gingivalis fimbrial-associated adhesins. DNA sequences adjacent to the 5' and 3' ends of the fimbrillin gene will be examined to determine whether the gene encoding for fimbrillin is part of a larger polycistonic unit that also contains other fimbrial-associated components. In order to further define the sHAP binding domains of the fimbrillin monomer, we propose to introduce site-directed mutations in the binding sites of fimbrillin domains identified in our previous studies. The mutant genes will be expressed as fusion proteins, purified, and tested in the in vitro system for adherence to sHAP or salivary components in solution. We will also pursue the direct approach of insertional inactivation of fimbrial gene and complementation studies. Mutant genes will be inserted into shuttle vectors which will be used to complement fimA gene deficient mutants generated in our laboratory. We will expand our studies to other strains of P. gingivalis by comparing the variable and constant epitopes of the 43 kDa fimbrillin subunit from several strains. Completion of these studies will provide, at the molecular level, an understanding of the antigenic heterogeneity observed among the strains. Synthetic peptides of the variable regions will be used to identify their role in attachment to salivary-coated HAP as well as in immune reactivity of fimbriae. Thus, the studies outlined in this subproject could provide important information needed for a rational approach for immunization to modulate colonization of the oral cavity.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Specialized Center (P50)
Project #
3P50DE008240-10S2
Application #
6104751
Study Section
Project Start
1997-12-01
Project End
1999-11-30
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
10
Fiscal Year
1998
Total Cost
Indirect Cost
Name
State University of New York at Buffalo
Department
Type
DUNS #
038633251
City
Buffalo
State
NY
Country
United States
Zip Code
14260
Ohkusa, Toshifumi; Yoshida, Tsutomu; Sato, Nobuhiro et al. (2009) Commensal bacteria can enter colonic epithelial cells and induce proinflammatory cytokine secretion: a possible pathogenic mechanism of ulcerative colitis. J Med Microbiol 58:535-45
Sojar, Hakimuddin T; Genco, Robert J (2005) Identification of glyceraldehyde-3-phosphate dehydrogenase of epithelial cells as a second molecule that binds to Porphyromonas gingivalis fimbriae. FEMS Immunol Med Microbiol 45:25-30
Satyanarayana, J; Gururaja, T L; Narasimhamurthy, S et al. (2001) Synthesis and conformational features of human salivary mucin C-terminal derived peptide epitope carrying Thomsen-Friedenreich antigen: implications for its role in self-association. Biopolymers 58:500-10
Narasimhamurthy, S; Naganagowda, G A; Janagani, S et al. (2000) Solution structure of O-glycosylated C-terminal leucine zipper domain of human salivary mucin (MUC7). J Biomol Struct Dyn 18:145-54
Sojar, H T; Han, Y; Hamada, N et al. (1999) Role of the amino-terminal region of Porphyromonas gingivalis fimbriae in adherence to epithelial cells. Infect Immun 67:6173-6
Mettath, S; Munson, B R; Pandey, R K (1999) DNA interaction and photocleavage properties of porphyrins containing cationic substituents at the peripheral position. Bioconjug Chem 10:94-102
Gururaja, T L; Levine, J H; Tran, D T et al. (1999) Candidacidal activity prompted by N-terminus histatin-like domain of human salivary mucin (MUC7)1. Biochim Biophys Acta 1431:107-19
Tseng, C C; Miyamoto, M; Ramalingam, K et al. (1999) The roles of histidine residues at the starch-binding site in streptococcal-binding activities of human salivary amylase. Arch Oral Biol 44:119-27
Naganagowda, G A; Gururaja, T L; Satyanarayana, J et al. (1999) NMR analysis of human salivary mucin (MUC7) derived O-linked model glycopeptides: comparison of structural features and carbohydrate-peptide interactions. J Pept Res 54:290-310
Satyanarayana, J; Gururaja, T L; Naganagowda, G A et al. (1998) A concise methodology for the stereoselective synthesis of O-glycosylated amino acid building blocks: complete 1H NMR assignments and their application in solid-phase glycopeptide synthesis. J Pept Res 52:165-79

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