Shigeno-Akutsu_1999_J.Biosci.Bioeng_88_484

The polyester-polyurethane (PUR)-degrading bacterium Comamonas acidovorans TB-35 produces two kinds of esterases, one cell-bound esterase (PUR esterase) and the other secreted in the culture broth (CBS esterase). In this study, the CBS esterase and the two recombinant esterases were purified. Identification of the physical and biochemical properties of the CBS and PUR esterases revealed that they have the same polypeptide from one gene. This finding was supported by the observation that Escherichia coli harboring the PUR esterase gene also produced two kinds of esterases. Though the PUR esterase degraded PUR and poly(diethylene glycol adipate), the soft segment of the PUR, the CBS esterase degraded only poly(diethylene glycol adipate). Furthermore, the hydrophobicity of the CBS esterase was lower than that of the PUR esterase. As the PUR esterase has been previously indicated to possess a PUR-binding domain, it was assumed that structural change around the PUR-binding domain of the CBS esterase was responsible for its inability to degrade PUR.