Binding behavior of PhaR to am-P(3HB) thin films. (A) Typical time courses of the frequency changes of am-P(3HB) coated on a QCM oscillator, in response to the addition of PhaR. (B) Saturation binding of PhaR to P(3HB). The curve was fitted with a sigmoid curve. [P(3HB)] = 200 μg cm-2 on a QCM, in 10 mM HEPES buffer solution (pH 7.4), 150 mM NaCl, and 0.001% Tween 20 at 25°C. (C) Binding behavior of PhaR to P(3HB) in response to change in the PhaR concentration. The arrow indicates the time of enzyme injection. (D) Linear reciprocal plots of the relaxation rate (τ-1) against PhaR concentrations according to Eq. (4) in the text.