Purification and Characterization of Two Chitosanase Isoforms from the Sheaths of Bamboo Shoots

Abstract

Two thermally stable chitosanase isoforms were purified from the sheaths of chitosan-treated bamboo shoots. Isoforms A and B had molecular masses of 24.5 and 16.4 kDa and isoelectric points of 4.30 and 9.22, respectively. Using chitosan as the substrate, both isoforms functioned optimally between pH 3 and 4, and the optimum temperatures for the activities of isoforms A and B were 70 and 60 °C, respectively. The kinetic parameters K(m) and V(max) for isoform A were 0.539 mg/mL and 0.262 μmol/min/mg, respectively, and for isoform B were 0.183 mg/mL and 0.092 μmol/min/mg, respectively. Chitosans were susceptible to degradation by both enzymes and could be converted to low molecular weight chitosans between 28.2 and 11.7 kDa. Furthermore, the most susceptible chitosan substrates were 50-70 and 40-80% deacetylated for isoforms A and B, respectively. Both enzymes could also degrade chitin substrates with lower efficacy. N-Bromosuccinimide and Woodward's reagent K strongly inhibited both enzymes.

Recovery and purification of chitosanase produced by Bacillus cereus using expanded bed adsorption and central composite design

“…This study was generally consistent with the results of packed purification of another chitosanase, reporting a final yield of 23.6 , 30 , and 17.1% . Regarding applications on unpacked bed purifications, these results are similar to the findings regarding the purification of a C‐phycocyanin , an E. coli ‐based therapeutic and β‐galactosidase .…”

Marine‐polysaccharide degrading enzymes: Status and prospects

“…Alkaline chitosanases have also been found, such as the chitosanase from Bacillus cereus GU-02 (optimum pH 9) (Goo & Park, 2014). The optimum temperatures for chitosanases activity are related to their sources and normally in the range 40 • C to 60 • C. Two thermally stable chitosanase isoforms were purified from the sheaths of chitosan-treated bamboo shoots, and their optimal temperatures were 70 • C and 60 • C, respectively (Hsu et al, 2012). A chitosanase with high activity at low temperatures has also been found-the chitosanase GsCsn46A showed 70% of its maximum activity at 15 • C and was suitable for controlled conversion of chitosan in mild reaction conditions (Qin et al, 2018).…”

“…Two isoforms of acidic chitosanases from the sheaths of bamboo shoots have been characterized. The optimum pH range for both isoforms is 3 to 4, and they retain 70% to 100% relative activity between pH 3 and 6 (Hsu, Chung, Chang, & Sung, 2012). Alkaline chitosanases have also been found, such as the chitosanase from Bacillus cereus GU‐02 (optimum pH 9) (Goo & Park, 2014).…”

Characterisation of an acidic peroxidase from papaya (Carica papaya L. cv Tainung No. 2) latex and its application in the determination of micromolar hydrogen peroxide in milk

“…The peroxidase obtained from the pAPMA-Sepharose 4B affinity column was concentrated using ultrafiltration with a 10-kDa MWCO membrane (Millipore). After dialysis against deionised water, the dialysate was brought to a total volume of 58 ml with H 2 O and loaded into the Rotofor cell chamber for IEF as described previously (Hsu, Chung, Chang, & Sung, 2012). The fractions containing acidic peroxidase activity (focusing at pH 3-5) were pooled and reloaded into the Rotofor cell chamber for refractionation.…”