A jacalin-related lectin domain-containing lipase from chestnut (Castanea crenata): Purification, characterization, and protein identification

A novel lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) was discovered from Korean chestnut (Castanea cren-ata). The lipase was isolated and purified by ammonium sulfate precipitation and a fast protein liquid chro-matography system equipped with HiTrap DEAE-Sepharose Fast Flow, HiTrap Q-Sepharose Fast Flow, and HiPrep Sephacryl S-100 Hi-Resolution columns. The purified C. crenata lipase showed a 15.8% yield, purification fold number of 465.8, and specific activity against triolein of 88.5 mU/mg. The enzyme exhibited hydrolytic activity toward tributyrin, trilaurin, and triolein, and was maximally active at pH 8.0 and 35 degrees C, with triolein used as the substrate. The activation energy (Ea) and deactivation energy (Ed) of triolein hydrolysis were 38.41 and 83.35 kJ/mol, respectively. In the enzyme kinetic study, Vmax, Km, and kcat were 110.58 mU/mg, 0.11 mM, and 0.221 min -1, respectively. The relatively low Km value indicated that the lipase has high affinity for its substrate. Moreover, Mg2+ and Ca2+ increased the lipase activity to 115.4% and 108.3%, respectively. The re-sults of peptide fingerprinting revealed that the C. crenata lipase with a molecular weight of 33.3 kDa was structurally similar to the mannose-binding lectin of the jacalin-related lectin domain superfamily, implying that it has potential as a therapeutic agent for use in the biomedical industry.

Automated summary

A novel lipase was discovered from Korean chestnut, showing high purification fold, specific activity against different triglycerides, and maximal activity at alkaline pH. The enzyme exhibited high affinity for its substrate and could be activated by Mg2+ and Ca2+. Its molecular structure was similar to a lectin in the biomedical field.