2eqt
From Proteopedia
Micelle-bound structure of growth-blocking peptide of the armyworm, Pseudaletia separata
Structural highlights
Function[GBP_MYTSE] Biogenic peptide that prevents the onset of metamorphosis from larva to pupa. Has repressive activity against juvenile hormone esterase. Induces cell proliferation at low concentrations and inhibits it at high concentrations. Mediates the spreading of plasmatocytes to foreign surfaces. May have a role in the regulation of dopamine concentrations.[1] [2] [3] Publication Abstract from PubMedGrowth-blocking peptide (GBP) is a hormone-like peptide that suppresses the growth of the host armyworm. Although the 23-amino acid GBP (1-23 GBP) is expressed in nonparasitized armyworm plasma, the parasitization by wasp produces the 28-amino acid GBP (1-28 GBP) through an elongation of the C-terminal amino acid sequence. In this study, we characterized the GBP variants, which consist of various lengths of the C-terminal region, by comparing their biological activities and three-dimensional structures. The results of an injection study indicate that 1-28 GBP most strongly suppresses larval growth. NMR analysis shows that these peptides have basically the same tertiary structures and that the extension of the C-terminal region is disordered. However, the C-terminal region of 1-28 GBP undergoes a conformational transition from a random coiled state to an alpha-helical state in the presence of dodecylphosphocholine micelles. This suggests that binding of the C-terminal region would affect larval growth activity. C-terminal elongation of growth-blocking peptide enhances its biological activity and micelle binding affinity.,Umetsu Y, Aizawa T, Muto K, Yamamoto H, Kamiya M, Kumaki Y, Mizuguchi M, Demura M, Hayakawa Y, Kawano K J Biol Chem. 2009 Oct 23;284(43):29625-34. Epub 2009 Aug 26. PMID:19710009[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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