The major thrust of the proposed studies is essentially two fold: (1) the isolation and characterization of the hCG/hLH receptor from superovulated rat ovaries and (2) the structure and function relationships in gonadotropins. The studies on hCG/hLH receptor will include (a) partial amino acid sequencing of the receptor subunits by a gas phase sequenator with the objective of using the sequence information to synthesize cDNA probes for the isolation and cloning of the receptor gene, (b) the determination of molecular properties of the receptor such as phosphorylation, glycosylation and acylation, and (c) production of monoclonal and polyclonal antibodies against the receptor. Structure and function studies will primarily focus on the role of carbohydrates in the function of gonadotropins. The cellular and molecular mechanisms of carbohydrate action in the hormonal signal transduction from hormone-receptor complex to the adenylate cyclase system and to the subsequent biological events will be studied. The effect of carbohydrate of the ligand on the induction of specific conformational change in the receptor, its desensitization and internalization will be investigated. The role of carbohydrate in eCG will also be studied and the effect of its removal on both its LH and FSH activities will be determined. The hCG specific antigenic site in DS5-hCG-Beta, a specific antigen obtained by the controlled reduction and alkylation of hCG-Beta, will be identified. This will be further confirmed by using synthetic peptide representing the hCG specific antigenic site and studying the inhibition of binding of DS5-hCG-Beta to its antibody by the peptide. Finally, the heterogeneity of carbohydrates in hCG, oLH and disease state hCG will be investigated by the newly developed thin layer chromatographic system. These basic studies on the receptor and hormone function would help in developing newer approaches to fertility regulation. Furthermore, the monoclonal antibodies to hCG-Alpha and hCG-Beta have potential in cancer diagnosis.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD008766-22
Application #
3310977
Study Section
Endocrinology Study Section (END)
Project Start
1977-12-01
Project End
1992-03-31
Budget Start
1988-04-01
Budget End
1989-03-31
Support Year
22
Fiscal Year
1988
Total Cost
Indirect Cost
Name
State University of New York at Buffalo
Department
Type
Schools of Arts and Sciences
DUNS #
038633251
City
Buffalo
State
NY
Country
United States
Zip Code
14260
Shao, K; Bahl, O P (1996) Preparation of recombinant carbohydrate deficient active analogs of human chorionic gonadotropin from insect cells. Prep Biochem Biotechnol 26:271-80
Chen, W; Bahl, O P (1992) Polyclonal antibodies against the polypeptide and carbohydrate epitopes of recombinant human choriogonadotropin beta-subunit. Mol Cell Endocrinol 86:57-66
Seth, P K; Bahl, O P (1991) Human choriogonadotropin-induced coupling of receptor and Gs protein and the effect of hormone deglycosylation. Mol Cell Endocrinol 80:105-14
Chen, W Y; Shen, Q X; Bahl, O P (1991) Carbohydrate variant of the recombinant beta-subunit of human choriogonadotropin expressed in baculovirus expression system. J Biol Chem 266:4081-7
Shen, Q X; Bahl, O P (1990) cDNA-derived amino acid sequences of choriocarcinoma alpha- and beta-subunits of human choriogonadotropin. Mol Cell Endocrinol 72:167-73
Chaturvedi, S; Bahl, O P (1990) Synthesis of cystine peptides 21-25/70-73 and 35-39/56-59 of the beta-subunit of human choriogonadotropin. Int J Pept Protein Res 35:133-40
Thotakura, N R; Weintraub, B D; Bahl, O P (1990) The role of carbohydrate in human choriogonadotropin (hCG) action. Effects of N-linked carbohydrate chains from hCG and other glycoproteins on hormonal activity. Mol Cell Endocrinol 70:263-72
Sojar, H T; Bahl, O P (1989) Characterization of rat ovarian lutropin receptor. Role of thiol groups in receptor association. J Biol Chem 264:2552-9
Sojar, H T; Bahl, O P (1987) A chemical method for the deglycosylation of proteins. Arch Biochem Biophys 259:52-7
Wagh, P V; Anumula, K R; Bahl, O P (1987) Keyhole limpet oligosaccharyl sulfatase. Methods Enzymol 138:816-25

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