Abstract:

Polyvinyl alcohol(PEG) and polyethylenamine(PEI) have been widely applied in the technological fields related to biochemistry. In this work, the interactions of amylase with PEG and tetraethylene pentamine(TEPA) were investigatied by fluorescence and UV absorption spectra. The results show both the inner fluorescence of amylase and the hydrophobicity of the microenvironment of tyrosine residues are enhanced in the presence of PEG. The quenching mechanism of inner fluorescence of amylase by TEPA is dynamic, but also exhibits a feature of static quenching. The polarity of microenvironment of tryptophan residues of amylase interacting with TEPA increases. In the range of this investigation, the binding constant of interaction of PEG with amylase reaches the highest value at 40 ℃, the value of quenching constant of binding between TEPA and amylase tends toward the maximum at 30 ℃. The interaction of amylse with PEG or TEPA involves hydrophobic and electrostatic interactions.

Key words: PEG, TEPA, amylase, interaction