• DOI:10.1006/BBRC.1993.1679
• Corpus ID: 10905667

Solution structure of trypsin modulating oostatic factor is a left-handed helix.

@article{Curto1993SolutionSO,
  title={Solution structure of trypsin modulating oostatic factor is a left-handed helix.},
  author={Ernest V. Curto and Michael A. Jarpe and J. Edwin Blalock and Dov Borovsky and N. Rama Krishna},
  journal={Biochemical and biophysical research communications},
  year={1993},
  volume={193 2},
  pages={
          688-93
        }
}

• E. Curto, M. Jarpe, +2 authors N. Krishna
• Published 15 June 1993
• Biology, Chemistry
• Biochemical and biophysical research communications

The solution structure of trypsin modulating oostatic factor (TMOF), a decapeptide (H-YDPAPPPPPP-OH) hormone that signals the termination of trypsin-like biosynthesis in mosquito midgut epithelial cells, was determined by 2-D 1H nuclear magnetic resonance spectroscopy and molecular modeling. The peptide forms a rod-shaped left-handed helix about 30 A long. No evidence was found to support a poly-L-proline beta-turn model. Hydrophobic contacts between the rings of tyrosine 1 and proline 3 may enhance the stability of the N-terminal segment. This peptide provides an interesting exception to the normal chemical shift index (csi) rules. Our results suggest that a sequence of positive csi indices, normally expected for a beta-strand structure, could also describe a left-handed poly-L-proline-like helix.