Spectroscopic and mechanistic analysis of the interaction between Jack bean urease and polypseudorotaxane fabricated with bis-thiolated poly(ethylene glycol) and α-cyclodextrin

摘要: Abstract Self-assembled polypseudorotaxanes (PPRXs) fabricated with α-cyclodextrin and poly(ethylene glycol) (PEG) or its thiolated derivatives were candidate functional materials for enzyme soft-immobilization, encapsulation controlled-release. The study of their interaction Jack bean urease (JBU) indicated that they inconspicuously influenced the activity stability JBU during long storage, up to 30 days. macro-species inaccessible JBU’s active site steric effect might play a significant role in stabilization JBU, when compared small-molecular sulfhydryl inhibitor thioglycolic acid. Circular dichroism fluorescence spectra analyses revealed PEG400-(SH)2 assembly PPRX400(SH) brought perturbations certain α-helical β-sheet domains making conformation more flexible. resulting partial unfolding exposed several hydrophobic clusters varied surface hydrophobicity. It also rendered chromophores hydrophilic bared polar environment, leading typical bathochromic-shift quenching intrinsic synchronous spectra. Moreover, hydrophobicity profile was depicted by fluorescent probe monitoring unique “hydrophobic cave” motif proposed analyzing structural data from Protein Data Bank. should be pointed out conformational variations mainly occurred at region while buried bi-nickel center not markedly macro-species. results demonstrated PPRXs act as proper carrier soft-immobilization.