Characterization of thermostable cyclodextrinase from Clostridium thermohydrosulfuricum 39E

Abstract

Clostridium thermohydrosulfuricum 39E produced a cell-bound cyclodextrin (CD)-degrading enzyme (cyclodextrinase). It was partially purified 205-fold (specific activity, 14.5 U/mg of protein) by solubilizing with Triton X-100, ammonium sulfate treatment, and DEAE-Sepharose CL-6B column chromatography. The enzyme activity was found to be stable at pH 5.5 and 60°C and optimally active at pH 6.0 and 65°C. The enzyme preparation hydrolyzed CDs, with α-CD > β-CD > γ-CD, and displayed a putative multiple attack pattern. The enzyme activity was inhibited by p-chloromercuribenzoate but not by N-bromosuccinimide.