title: Oxidative folding of peptides with cystine-knot architectures: kinetic studies and optimization of folding conditions.
abstract: Bioactive peptides often contain several disulfide bonds that provide the main contribution to conformational rigidity and structural, thermal, or biological stability. Among them, cystine-knot peptides-commonly named "knottins"-make up a subclass with several thousand natural members. Hence, they are considered promising frameworks for peptide-based pharmaceuticals. Although cystine-knot peptides are available through chemical and recombinant synthetic routes, oxidative folding to afford the bioactive isomers still remains a crucial step. We therefore investigated the oxidative folding of ten protease-inhibiting peptides from two knottin families, as well as that of an HIV entry inhibitor and of aprotinin, under two conventional sets of folding conditions and by a newly developed procedure. Kinetic studies identified folding conditions that resulted in correctly folded miniproteins with high rates of conversion even for highly hydrophobic and aggregation-prone peptides in concentrated solutions.
authors.affiliation: Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Petersenstr. 22, 64287 Darmstadt, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Reinwarth
authors.forename: Bernhard
authors.initials: B
authors.lastname: Glotzbach
authors.forename: Michael
authors.initials: M
authors.lastname: Tomaszowski
authors.forename: Sebastian
authors.initials: S
authors.lastname: Fabritz
authors.forename: Olga
authors.initials: O
authors.lastname: Avrutina
authors.forename: Harald
authors.initials: H
authors.lastname: Kolmar
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000595:Amino Acid Sequence; D007611:Aprotinin / Q000737:chemistry; D002021:Buffers; D003553:Cystine / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D019791:Guanidine / Q000737:chemistry; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D014270:Trifluoroethanol / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D002021:Buffers; D004220:Disulfides; D010446:Peptide Fragments; D003553:Cystine; D014270:Trifluoroethanol; D007611:Aprotinin; D019791:Guanidine; D004121:Dimethyl Sulfoxide; C032159:acetonitrile