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Oxidative folding of synthetic polypeptides S ‐protected as tert ‐butylthio derivatives
Author(s) -
Verdini Antonio,
Terenzi Silvia,
Brossard Vincent,
Roggero Mario,
Corradin Giampietro
Publication year - 2008
Publication title -
journal of peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 66
eISSN - 1099-1387
pISSN - 1075-2617
DOI - 10.1002/psc.1067
Subject(s) - chemistry , oxidative folding , cleavage (geology) , peptide , disulfide bond , cysteine , oxidative phosphorylation , alkylation , combinatorial chemistry , stereochemistry , biochemistry , protein disulfide isomerase , catalysis , fracture (geology) , engineering , enzyme , geotechnical engineering
A new method for oxidative folding of synthetic polypeptides assembled by stepwise solid phase synthesis is introduced. Folding is obtained in excellent yields by reacting S ‐ tert ‐butylthiolated polypeptides with a 100‐fold molar excess of cysteine at 37 °C in a slightly alkaline buffer containing chaotropic salts, and in the presence of air‐oxygen. This novel protocol has been applied to the folding of S ‐ tert ‐butylthiolated human thymus and activation‐regulated chemokine (hu‐TARC) derivatives as well as to larger segments of Plasmodium falciparum and Plasmodium berghei circumsporozoite proteins. Folded P. falciparum polypeptides have been used as substrates of endoproteinase Glu‐ C (Glu‐ C ) and endoproteinase Asp‐ N (Asp‐ N ) in an attempt to identify their disulfide connectivities. Particular practical advantages of the present method are (i) easy purification and storage of the S ‐protected peptide derivatives, (ii) elimination of the risk of cysteine alkylation during the acidolytic cleavage deprotection and resin cleavage steps, (iii) possibility to precisely evaluate the extent of folding and disulfide bond formation by mass spectrometry, and (iv) facile recovery of the final folded product. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.