Conformational study based on simulated annealing and 1H NMR of peptides comprising the consensus sequence Arg5-Asp-Val-Arg-Gly9: effects of the substitution Ser 12 by Ala 12 or of 3 residues deletion at the N-terminus.
A conformational search by simulated annealing has been performed on two peptides derivated from the tetradecapeptide used to isolate the Xenopus laevis skin maturation RXVRG-endoprotease. The Ala 12 derivative, obtained by substitution in the hydrophobic C terminal fragment and the undecapeptide 4-14, obtained by deletion of an acidic rich tripeptide, were studied. No unique structure has been found for the tetradecapeptide Ala 12. This structural disorganization could explain the loss of activity of the endoprotease towards the substituted peptide. For the undecapeptide, two different models in accordance with the NMR data were found. The conformational differences between these two models are located in the consensus sequence and in each case an hairpin-like conformation is observed. These results could be related to the enhanced cleavage activity of the maturation enzyme. The obtained structures are also compared with those of the original tetradecapeptide.
L.P.C.B., Institut Curie et Universite Paris VI, France.
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Meddeb
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Baron
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Riand
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Ballini
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Vigny
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Demaret
D000409:Alanine; D000595:Amino Acid Sequence; D000818:Animals; D003198:Computer Simulation; D016384:Consensus Sequence; D009682:Magnetic Resonance Spectroscopy; D008666:Metalloendopeptidases / Q000378:metabolism*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D012694:Serine; D013329:Structure-Activity Relationship; D014982:Xenopus laevis
D009842:Oligopeptides; D012694:Serine; D008666:Metalloendopeptidases; C090338:RXVRG endoprotease; D000409:Alanine