Covalent Binding of Alkaline Phosphatase on Porous Supports and the Stability of the Immobilized Enzyme

摘要

Alkaline phosphatase was covalently bound to a series of porous silicas and controlled-pore glasses using different silanization procedures and derivatization methods in order to determine the conditions that would lead to the highest immobilized enzyme (IME) activity and stability. Aqueous silanization was found to give more controlled surface coverage of the porous support than toluene silanization; aqueous silanization also resulted in more stable IMEs. Nearly identical IME activities were obtained with aqueous silanization and three different derivatization methods. The IME formed with diisothiocyanate derivatization had the greatest stability in cold, dry storage but the poorest stability in cold, alkaline buffer. IMEs formed with glutaraldehyde were consistently more stable than those IMEs formed with carbodiimide derivatization. Keywords: Thin films; Films; Immobilized enzymes. (kt)