Thermal deactivation studies of alpha-amylase immobilized onto core-shell structured aniline formaldehyde crosslinked polyaniline magnetic nanocomposite

Abstract

This study involves immobilizing α -amylase onto an aniline formaldehyde condensate cross-linked polyaniline magnetic nanocomposite (AFCCLPANIMg). To our knowledge, the utility of AFCCLPANIMg with a core-shell structure in enzyme immobilization has not received sufficient attention. The kinetic parameters were determined under optimal conditions, and the immobilized enzyme had a higher Km value and a lower Vmax value than the free enzyme, owing to the enzyme’s conformational shift. The immobilized enzyme preserved 45% of its original activity after 12 cycles and 59% of its activity in 4-week storage stability testing. The thermal deactivation of the free and immobilized enzyme followed first-order kinetics. The D-values, t1/2 and z value of the immobilized enzyme indicated better thermal stability than that of the free enzyme. The immobilized enzyme’s high Ed value of 19.92 19.92 kJ mol−1 defined its strong stability and resistance to heat inactivation.

Keywords

• Nanocomposite
• α-amylase
• immobilization
• thermal stability
• thermal deactivation