AtSS1 activation and deactivation mediated by recombinant AtTrxs.

Reactivation of oxidized AtSS1: protein was first oxidized by CuCl₂, and then it was desalted and treated with water, reduced Trxs and DTTred. Trxs (100 μM) were reduced with 0.5 mM DTTred. Deactivation of reduced AtSS1: protein was first reduced by DTTred, and then it was desalted and treated with water, oxidized Trxs and CuCl₂. Trxs (150 μM) were oxidized with 300 μM CuCl₂. Fully reduced sample was set as 100%. Desalting control (sample treated identically to oxidized Trxs but Trxs were omitted) was used to test that CuCl₂ left after desalting is not the major deactivating factor. Activity was assayed by SCGA using maltotriose as acceptor; results are the mean of two technical replicates (±SD).