Physicochemical and biological characterizations of pregnant mare serum gonadotropin and its subunits.
Abstract: Pregnant mare serum gonadotropin and its subunits have been further characterized. Ultracentrifugation of the gonadotropin at pH 1.3 and 11.5 showed little evidence of dissociation compared to pH 8.2. Highly purified subunits are obtained by urea dissociation and ion-exchange chromatography followed by gel-filtration. Circular dichroism spectra of the gonadotropin and its subunits are much like those of ovine lutropin and its subunits in that there is little evidence for secondary structure and one or more tyrosine residues are inaccessible in the intact gonadotropin compared to the subunits. The alpha-subunit possesses almost 3 times as much total carbohydrate as the beta-subunit; the individual sugar composition of each was determined as well as the amino acid composition. The alpha-subunit begins with the sequence NH2-Phe-Pro (Gly or Pro) ... and terminates with isoleucine. The beta-subunit has the sequence NH2-Ser-Pro-Gly ...; no C-terminal residue is detectable by either carboxypeptidase or hydrazinolysis. Biological studies show the gonadotropin to be active in assays specific for both lutropin and follitropin. Precipitin test in agar with rabbit antiserum against the gonadotropin show that the beta subunit cross-reacts whereas the alpha subunit does not.
Publication Date: 1978-01-25 PubMed ID: 413583DOI: 10.1016/0005-2795(78)90462-2Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- U.S. Gov't
- P.H.S.
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The researchers have conducted an in-depth analysis of pregnant mare serum gonadotropin and its two subunits, providing key information about their structure and biological function.
Research Methodology
- The research process started with the characterization of pregnant mare serum gonadotropin and its individual subunits, identified as alpha and beta.
- The gonadotropin was subjected to ultracentrifugation at different pH values (1.3, 8.2, and 11.5) to investigate any evidence of dissociation.
- Further purification of the gonadotropin’s subunits was achieved through a combination of urea dissociation, ion-exchange chromatography, and gel-filtration.
- The research also incorporated circular dichroism spectra to look at the secondary structures of the gonadotropin and its subunits.
- The composition of each subunit was then determined using amino acid analysis, sugar composition assessment, and sequence identification.
- Finally, biological studies were conducted to determine the activity and reactivity of the gonadotropin and its subunits.
Research Findings
- Ultracentrifugation of the gonadotropin showed little evidence of dissociation at extreme pH values. This suggests that the gonadotropin is stable across a broad pH range.
- Circular dichroism spectra revealed little evidence for secondary structure in the gonadotropin and its subunits.
- The research found one or more tyrosine residues were inaccessible in the intact gonadotropin compared to the subunits, similar to observations made for ovine lutropin (a hormone in sheep).
- The alpha-subunit was found to have almost three times the total carbohydrate content of its beta counterpart.
- Sequence analysis showed that each subunit has distinct beginning and terminating sequences. The alpha-subunit begins with NH2-Phe-Pro (Gly or Pro) and ends with isoleucine, while the beta-subunit starts with NH2-Ser-Pro-Gly but does not have a detectable C-terminus.
- The gonadotropin was found to be biologically active in assays specific for lutropin and follitropin, two types of hormones.
- A precipitin test (a type of immunoassay) showed the beta subunit cross-reacted with rabbit antiserum against the gonadotropin, while the alpha subunit did not.
Conclusion
- The research provides a comprehensive study of the physical and biological properties of pregnant mare serum gonadotropin and its subunits.
Cite This Article
APA
Papkoff H, Bewley TA, Ramachandran J.
(1978).
Physicochemical and biological characterizations of pregnant mare serum gonadotropin and its subunits.
Biochim Biophys Acta, 532(1), 185-194.
https://doi.org/10.1016/0005-2795(78)90462-2 Publication
Researcher Affiliations
MeSH Terms
- Amino Acids / analysis
- Animals
- Biological Assay
- Carbohydrates / analysis
- Chorionic Gonadotropin / pharmacology
- Circular Dichroism
- Female
- Follicle Stimulating Hormone / metabolism
- Gonadotropins, Equine / pharmacology
- Immunodiffusion
- Leydig Cells / drug effects
- Luteinizing Hormone / metabolism
- Macromolecular Substances
- Male
- Ovary / drug effects
- Protein Conformation
- Rats
- Testosterone / metabolism
Citations
This article has been cited 2 times.- Candelaria NR, Padmanabhan A, Stossi F, Ljungberg MC, Shelly KE, Pew BK, Solis M, Rossano AM, McAllister JM, Wu S, Richards JS. VCAM1 Is Induced in Ovarian Theca and Stromal Cells in a Mouse Model of Androgen Excess.. Endocrinology 2019 Jun 1;160(6):1377-1393.
- Kirschenbaum DM. A compilation of amino acid analyses of proteins. XVIII. Residues per thousand residues--5.. Appl Biochem Biotechnol 1983 Aug;8(4):315-68.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
