Reversible immobilization of soybean beta-amylase on phenylboronate-agarose.
Soybean beta-amylase (EC 3.2.1.2) wap immobilized on phenylboronate-agarose by strong interactive binding. The insoluble derivative was active and more stable to temperature changes than the free enzyme. The absence of enzyme leakage even in the presence of substrate was demonstrated. Changes in pH over a wide range (4.0-8.0) did not affect the stability of the complex. The support could be recovered by sorbitol elution, which demonstrated the reversibility of the binding. Since the enzyme was not retained on phenylagarose under similar conditions, we rejected hydrophobic interactions as a cause of the strong binding of the enzyme to phenylboronate-agarose. We suggest that the bonding of the enzyme to the phenylboronate ligand occurs by a charge transfer mechanism between the trigonal boronate and the side chain nitrogenated groups. It was concluded that phenylboronate-agarose has good properties as a support, which recommends its use for the preparation of immobilized enzymes.
Viera
F B
FB
Catedra de Bioqulmica, Facultad de Quimica, Gral. Floras 2124, Casilla de Correo 1157, Montevideo, Uruguay.
Barragan
B B
BB
Busto
B L
BL