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NMR Structural Studies of Stress Responsive Peptide‐2 from the Insect Manduca sexta
Author(s) -
Schrag Lynn,
Cao Xiaolong,
Herrera Alvaro I,
Wang Yang,
Jiang Haobo,
Prakash Om
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.913.21
Subject(s) - manduca sexta , peptide , biochemistry , serine protease , peptide sequence , nuclear magnetic resonance spectroscopy , biology , protein structure , residue (chemistry) , chemistry , protein secondary structure , manduca , stereochemistry , serine , insect , gene , protease , enzyme , botany
With the genome sequence of Manduca sexta available, we have identified ten open reading frames coding for precursors of paralytic peptide (PP) homologs: uENF1, uENF2, and SRP1–8. While uENF1 and uENF2 are located upstream of the PP gene, we temporarily call the other eight stress responsive peptides (SRPs), since stress is broader than infection, a type of biotic stresses. SRP2 is predicted to be a 25‐residue peptide (FGVKDGKCPSGRVRRLGICVPDDDY) stabilized with a disulfide bond. The proteolytic activation of proSRP2 is likely linked to the serine protease network that mediates and coordinates immune responses in this insect. SPR2 may also participates as a regulator in brain development. We have determined the solution structure of SRP2 by two‐dimensional 1 H NMR spectroscopy to begin to understand structural‐functional relationships of this peptide. Our preliminary studies indicate that SRP2 has an ordered structure, which is composed of two short β‐strands at residues Arg 12 ‐ Arg 15 and Ileu 18 ‐Val 20 , one type I′ β‐turns at residues Arg 15 ‐Ileu 18 and a γ′‐turn at residues Cys 8 ‐ Ser 10 . Work is in progress towards 3D structure determination. Based on our NMR data, a well‐defined secondary and tertiary structure for this class of peptides will be presented.