Abstract: The α-glucosidase was immobilized on chitosan with a novel coupling reagent-tris(hydroxymethyl)phosphine (THP). The optimum condition of immobilization was investigated, and the results showed that: the quantity of chitosan, THP, and α-glucosidase(0.1U/ml) was 70mg,250mg, and 1μl respectively; the pretreated chitosan could sieve into a particle size of 120 mesh and it’s deacetylation was 93%; synthesis of chitosan-THP was achieved in 8 min;synthesis THP and chitosan-THP must be completed in 1h without N protection, the coupling reaction between α-glucosidase and chitosan-THP was done in 2 the condition of pH6.0 for 2h; all the immobilization process was accomplished in room temperature except the coupling reaction between α-glucosidase and chitosan-THP at 5℃. The experiment showed that the activity of the immobilized α- glucosidase was 0.229(absorbance at 400nm), 9 times than the activity of the immobilized one used glutaraldehyde as coupling reagent, and it’s immobilization yield was 41.2%; in addition, the stability of immobilized α-glucosidase for enduring pH changing, organic solvent, heat, and long-time storing was much better than the nature one’s and the stable of immobilized one’s with glutaraldehyde as coupling reagent.

Key words: immobilization, α-glucosidase, tris(hydroxymethyl)phosphine, glutaraldehyde