General review on the oxidative folding of small disulfide-rich proteins are available
[Arolas et al, 2006;
Craik 2010].
|
α-Amylase Inhibitor
|
Oxydative folding of AAI
involves intermediates with nonnative disulfide bridges between
adjacent cycteines
The folding pathway of the α-Amylase Inhibitor AAI from
Amaranthus has been analyzed using RP-HPLC, LC-MS, 1H-NMR and
photochemically induced dynamic nuclear polarization (photo-CIDNP)
experiments [Cemazar
et al., 2003].
Folding of AAI proceeds through several fully oxydized intermediates
with nonnative disulfide bridges.
The major folding intermediate (MFI) is shown to contain
a disulfide bridge between adjacent cysteine residues,
i.e. Cys60 and Cys61 according to the knottin
unique numbering.
A clear interdependence between the formation of disulfide
bridges and conformational folding is demonstrated [Cemazar
et al., 2004]. It is proposed that formation of nonnative
disulfide bridges facilitates folding by reducing the entropy
of the unfolded state. Then the conversion from nonnative disulfide
bridges to native disulfide bridges is driven by the formation
of native stabilizing non-bonding interactions. |