Conformation-dependent side reactions in interstrand-disulfide bridging of trimeric collagenous peptides by regioselective cysteine chemistry.
Conversion of single-chain or disulfide-bridged dimeric collagenous peptides into Cys(Npys) derivatives as activated species for subsequent regioselective thiol/disulfide exchange reactions leads to side products whose origin and nature was determined by HPLC and ESI-MS. In both cases the high tendency of the educts to self-associate into triple-helical homotrimers, as assessed by their dichroic properties in the reaction media, is responsible for the failure of this well established cysteine chemistry. Only by optimizing the synthetic strategy or by exploiting a kinetic control of the reaction, could these conformation-dependent limitations be more or less efficiently bypassed for the regioselective assembly of heterotrimeric collagen model peptides crosslinked with artificial cystine knots.
Saccá
Barbara
B
Max-Planck-Institut für Biochemie, Martinsried, Germany.
Barth
Dirk
D
Musiol
Hans-Jürgen
HJ
Moroder
Luis
L
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry*; D019281:Dimerization; D004220:Disulfides / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D021241:Spectrometry, Mass, Electrospray Ionization
D004220:Disulfides; D010455:Peptides; D003094:Collagen; D003545:Cysteine