Research interest in my laboratory has been on the structure-function relationship of biologically active proteins and glycoproteins. We are interested in studying the regulation of mucin glycoprotein biosynthesis and how the repertoire of glycosyltransferases regulates the sites of mucin O-glycosylation. The facilities in our laboratory include Applied Biosystems 473A liquid/gas phase sequencer, capillary electrophoresis system, peptide synthesizer, amino acid analyzer, Voyager DE-STR MALD-TOF mass spectrometer, and several HPLC systems.

We are also interested in studying the virulence factors of the oral pathogens and development of agents which can inhibit the adherence of oral pathogens. One of the on going research project deals with the development of Carbohydrate-based Peptidomimetics to prevent Candidiasis. The goal of this research grant proposal is to test the hypothesis that peptidomimetics of specific cell-surface carbohydrate structures can be used to reduce the level of the in vivo oral candidiasis, which accompanies salivary gland hypofunction. Peptide libraries prepared using both phage display and synthetic chemical approach are being screened for peptides which bind to either anti-candida albican mannan or Ulex europeus lectin. Selected mimetics will be tested in vivo with a surgical desalivated rat model system.

Another research project studies the association of caries and salivary analytes. Monoclonal and polyclonal antibodies are being generated against salivary proteins and microbial components. We will develop sandwich enzyme-linked immunoassays (ELISA) to quantitate the levels of salivary proteins, glycosyltransferases from Streptococcus mutans, and food preservative benzoate in 4000 samples of resting saliva samples. The comprehensive survey and the cluster analysis of multiple salivary components should generate a useful data set to test for the association of these components with the carries experience and to identify parameters that will indicate increased risk for dental caries.

Another area of research interest is the proteomic analysis of human salivary glands to map the spectrum of proteins which are secreted by the normal human parotid and submandibular/ sublingual glands. Proteins are separated by two-dimensional gel electrophoresis and Western blotting and are identified by MALDI-TOF or Edman degradation. Samples from normal and idiopathic dry mouth patients will be compared to identify proteins which differ in their levels of expression.

Bedi, G.S. (1997). Structural studies of the Asn-linked carbohydrate chains of inducible rat parotid proline-rich glycoprotein. Glycoconjugate J. 14:907-916.

Bedi, G.S., T. Zhou, and S.K. Bedi (1998). Production of rat salivary cystatin variant polypeptides in Escherichia coli. Arch. Oral Biol. 43:173-182.

Ten Hagen, K.G., D. Tetaert, F.K. Hagen, C. Richet, T.M. Beres, J. Gagnon, M.M. Balys, B. VanWuyckhuyse, G.S. Bedi, P. Degand, and L.A. Tabak (1999). Characterization of a UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase which displays glycopeptide N-acetylgalactosaminyltransferase activity. J. Biol. Chem. 274:27867-27874.