Covalent binding of proteins and glucose-6-phosphate dehydrogenase to cellulosic carriers activated with s-triazine trichloride

A method was developed for covalently binding proteins and enzymes to cellulosic carriers such that the enzymes retained high specific activity. Optimal conditions for activating the carriers with s-triazine trichloride were found to be: (a) pretreatment of cellulose with 3 m NaOH; and (b) reaction with 5% ($\text{w}\text{w}$) s-triazine trichloride in dioxane-xylene (1:1 $\text{w}\text{w}$) for 30 min at room temperature. All proteins tested bound most readily at pH values below pH 7. Extensive investigation of immobilized glucose-6-phosphate dehydrogenase showed that: (a) over 80% of the specific activity of the enzyme was retained; and (b) the pH optimum and K_m values were not altered significantly from that of the free enzyme. The binding method has been applied successfully to hexokinase, phosphorylase and pronase.