Ca2+-based metal-organic framework as enzyme preparation to promote the catalytic activity of amylase

Enzyme preparation can protect the enzyme conformation in storage, transportation, and operation process, but excessive additives can affect enzyme performance. In this work, a Ca2+-based metal-organic framework (UTSA-280) was prepared to encapsulate amylases (α-amylase, pullulanase, and glucoamylase) in situ. After release from UTSA-280, the relative activity of α-amylase and pullulanase increased to 177.8 and 201.0%, respectively, as compared to pure enzymes. Mechanism explorations indicate that amylase released from UTSA-280 has more Ca2+ on its surface with stronger combination, which probably leads to the activation effect to metal ion activating enzyme. Besides, UTSA-280 could protect enzymes from heat, organic solvent, and trypsin, which is beneficial for the storage, transportation, and operation of enzyme. Therefore, it is concluded that metal-organic frameworks could be a promising metal ion activating enzyme preparation material with activity promoting and protective effects.