Reversible folding of rhodanese

摘要: Abstract For the first time completely reversible unfolding was achieved for guanidinium chloride-denatured rhodanese using a systematically defined protocol. These conditions included beta-mercaptoethanol, lauryl maltoside, and sodium thiosulfate. All components were required to get more than previous best reactivation with maltoside of 17% (Tandon, S., Horowitz, P. (1986) J. Biol. Chem. 261, 15615-15681). Non-coincidental transition curves obtained by monitoring different parameters including: (i) variation in activity, (ii) shifts fluorescence wavelength maximum, (iii) ellipticity at 220 nm. The followed maximum asymmetric resolvable into two separate transitions. A thermodynamic analysis used define energetics processes. Studies fluorescent "apolar" probe 1,8ANS are consistent appearance organized hydrophobic surfaces following transition. Near UV CD measurements indicated that is associated loss dyssymmetry around least some tryptophans. Thus, complex, there detectable intermediate(s) during process. results suggest occurs discrete stages: 1) tertiary interactions retention secondary structure, 2) structure. available x-ray structure suggests can be changes domain interactions, which may modulate effectiveness helix dipoles lowering pKa active site sulfhydryl.