Improving the Heat Resistance of β-1,4 Glucanase by Introducing Disulfide Bonds.

Each possible pair of residues in β-1,4 glucanase for disulfide formation was assessed using online websites, and four pairs L28C-S256C, Q41C-P278C, S122C-N163C and A184C-A215C were selected. Accordingly, four recombinant plasmids pET28a (+) EccslH28, pET28a (+) EccslH41, pET28a (+) Eccs-1H122 and pET28a (+) EccslH184 were prepared and transformed into E. coli to express the recombinant enzymes. Then analysis on enzymatic properties showed that T50 of the recombinant enzymes was increased from 10 min for EccslHt2 to 90 min for EccslH28 and 40 min for EccslH41 at 70 °C, while their optimum pH value and pH stability were not affected, which proved that the introduction of disulfide bond improved the thermal stability of β-1,4 glucanase. [ABSTRACT FROM AUTHOR]