Properties of firefly luciferase immobilized through a biotin carboxyl carrier protein domain

A fusion protein, consisting of biotin carboxyl carrier protein (BCCP) doma in from Escherichia coli and firefly luciferase (FL) from Photinus pyralis, was immobilized through the biotin-avidin interaction on 6%, cross-linked agarose beads. Several properties of the immobilized BCCP-FL were studied. Immobilized and free enzymes showed no significant difference in thermal st ability; both retained at least 91% activity after incubation at 4 degreesC and 25 degreesC for 22 h. Incubation at 37 degreesC for 22 h caused signif icant activity loss. K-M and k(cat) values were determined for both free an d immobilized enzymes. K-M values were similar between free and immobilized enzymes; however, k(cat) of immobilized BCCP-FL, was one-third of the k(ca t) of the free enzyme. 294 mu mol/L Co-enzyme A (CoA) and 44 mmol/L dithiot hreitol (DTT) enhanced the total bioluminescence output. Triton X-100, Twee n 20. PEG 8,000, PVP 40,000 and PVP 360,000 did not enhance the bioluminesc ence reaction of immobilized BCCP-FL. Copyright (C) 2001 John Wiley & Sons, Ltd.