Non-native hydrophobic interactions detected in unfolded apoflavodoxin by paramagnetic relaxation enhancement.

ABSTRACT: Transient structures in unfolded proteins are important in elucidating the molecular details of initiation of protein folding. Recently, native and non-native secondary structure have been discovered in unfolded A. vinelandii flavodoxin. These structured elements transiently interact and subsequently form the ordered core of an off-pathway folding intermediate, which is extensively formed during folding of this alpha-beta parallel protein. Here, site-directed spin-labelling and paramagnetic relaxation enhancement are used to investigate long-range interactions in unfolded apoflavodoxin. For this purpose, glutamine-48, which resides in a non-native alpha-helix of unfolded apoflavodoxin, is replaced by cysteine. This replacement enables covalent attachment of nitroxide spin-labels MTSL and C

SUBMITTER: Nabuurs SM 

PROVIDER: S-EPMC2841281 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature