Related Experiment Videos
Correlation of structural changes in parathyroid hormone with its vascular action
Peptides
|November 1, 1986
Summary
Oxidizing methionine in bovine parathyroid hormone peptide (bPTH(1-34)) altered its structure, reducing its hypotensive effect. Arginine modification also decreased vascular activity, suggesting conformational changes inactivate bPTH(1-34).
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- Bovine parathyroid hormone peptide (bPTH(1-34)) is a vasoactive hormone.
- Methionine oxidation and arginine modification are known to affect peptide structure and function.
Purpose of the Study:
- To investigate the impact of methionine oxidation and arginine modification on the structure and vascular activity of bPTH(1-34).
Main Methods:
- Circular dichroism (CD) spectroscopy to analyze conformational changes.
- Tryptophan fluorescence and TNS fluorescence assays to assess hydrophobicity.
- In vivo hypotensive response testing in rats.
Main Results:
- Methionine oxidation converted ~43% of ordered structure (alpha-helix, beta-sheet) to random coil.
- Oxidation increased hydrophobicity and abolished hypotensive response.
- Arginine modification with 1,2-cyclohexanedione (CHD) reduced hypotensive action by 30-50% and increased hydrophobicity.
Conclusions:
- Conformational changes induced by methionine oxidation or arginine modification are linked to the inactivation of bPTH(1-34)'s vascular activity.