Structure of the insect cytokine peptide plasmatocyte-spreading peptide 1 from Pseudoplusia includens

J Biol Chem. 1999 Feb 19;274(8):4493-6. doi: 10.1074/jbc.274.8.4493.


The structure of the recently identified plasmatocyte spreading peptide from the moth Pseudoplusia includens (PSP1) has been determined by NMR spectroscopy. This novel insect cytokine consists of 23 amino acid residues and a single disulfide bond. Torsion angle dynamics calculations utilizing a total of 337 distance constraints yielded an ensemble of 30 structures with an average backbone root mean square deviation for residues 7-22 of 0.18 A from the mean structure. The structure consists of a disordered N-terminal region and a well defined core that is stabilized by numerous hydrophobic interactions and a short beta-hairpin. Structural comparisons confirm that PSP1 adopts an epidermal growth factor (EGF)-like fold with close similarity to the C-terminal subdomain of EGF-like module 5 of human thrombomodulin. The combination of the three-dimensional structure of PSP1 and the extensive literature on EGF-receptor interactions should accelerate the process of identifying the specific residues responsible for receptor binding activity of this family of immunoregulatory peptides.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Epidermal Growth Factor / chemistry
  • Humans
  • Intercellular Signaling Peptides and Proteins
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Molecular Sequence Data
  • Moths / chemistry*
  • Peptides / chemistry*
  • Protein Structure, Tertiary
  • Sequence Homology, Amino Acid


  • Intercellular Signaling Peptides and Proteins
  • Peptides
  • plasmatocyte-spreading peptide 1
  • Epidermal Growth Factor

Associated data

  • PDB/1B1V
  • PDB/1B5N