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Structure of P401 (mast cell degranulating peptide) in solution
N V Kumar1, D E Wemmer, N R Kallenbach
1Department of Chemistry, University of California, Berkeley 94720.
Biophysical Chemistry
|August 1, 1988
Summary
Mast cell degranulating protein (P401) from honeybee venom shares structural similarities with apamin. NMR analysis reveals P401 adopts an extended N-terminus and an alpha-helical C-terminus, connected by tight turns.
Area of Science:
- Biochemistry
- Structural Biology
- Venomics
Background:
- P401 (mast cell degranulating protein, MCD) is a minor component of honeybee venom.
- Its primary structure is related to apamin, another well-studied bee venom peptide.
Purpose of the Study:
- To elucidate the solution structure of P401 using high-resolution NMR spectroscopy.
- To compare the structural conformation of P401 with apamin.
Main Methods:
- High-resolution two-dimensional 1H-NMR spectroscopy was employed to study P401 in solution.
- Sequential assignment strategy was used to assign backbone proton resonances.
- Nuclear Overhauser Effect (NOE) analysis was performed to determine structural conformation.
Main Results:
- Almost all backbone proton resonances of P401 were successfully assigned.
- NOE analysis indicated a conformation highly similar to that of apamin.
- Specific structural features were identified: an extended conformation from Ile-1 to Cys-5 and an alpha-helical structure from His-13 to Asn-22.
Conclusions:
- P401 exhibits a distinct three-dimensional structure in solution, characterized by an extended N-terminus and an alpha-helical C-terminus.
- These structural elements are linked by two tight turns, contributing to the overall fold.
- The structural similarity to apamin suggests potential shared biological functions or evolutionary origins.