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Synthesis and Structure Determination of µ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities
Published on: October 2, 2018
Hepcidin revisited, disulfide connectivity, dynamics, and structure.
John B Jordan1, Leszek Poppe, Mitsuru Haniu
1Department of Molecular Structure, Amgen, Inc., Thousand Oaks, California 91320, USA. jbjordan@amgen.com
The Journal of Biological Chemistry
|June 26, 2009
Summary
Researchers identified a new disulfide bonding pattern for hepcidin, the key regulator of iron homeostasis. This finding, confirmed by multiple techniques, reveals a novel structural model for this important peptide hormone.
Area of Science:
- Biochemistry
- Structural Biology
- Molecular Medicine
Background:
- Hepcidin is a critical peptide hormone regulating iron homeostasis in vertebrates.
- Previous studies suggested a different disulfide bonding pattern for hepcidin.
Purpose of the Study:
- To elucidate the correct disulfide bonding pattern of hepcidin.
- To determine the solution structure of hepcidin and its conformational dynamics.
Main Methods:
- Multiple biochemical and biophysical techniques were employed.
- Nuclear Magnetic Resonance (NMR) spectroscopy was used to study hepcidin structure and dynamics.
- X-ray crystallography was utilized to analyze a hepcidin-Fab co-crystal.
Main Results:
- A novel disulfide bond connectivity for hepcidin was confirmed: Cys(1)-Cys(8), Cys(3)-Cys(6), Cys(2)-Cys(4), and Cys(5)-Cys(7).
- NMR studies revealed that hepcidin exists in two interconverting conformations at ambient temperatures.
- The solution structure was determined at different temperatures, and X-ray analysis stabilized a conformation consistent with the high-temperature NMR structure.
Conclusions:
- The established disulfide bonding pattern and structural model provide a more accurate understanding of hepcidin's function.
- Hepcidin's conformational flexibility may be crucial for its role in iron regulation.
- These findings offer insights into the molecular mechanisms of iron homeostasis.
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