Surface plasmon resonance study of interaction between lactoferrin and naringin

Lactoferrin (LF) is a glycoprotein that serves as a potential vehicle for small bioactive molecules in food. In an effort to improve this functionality, the kinetic and thermodynamic interaction of LF with naringin (NR) was studied by surface plasmon resonance (SPR). The results demonstrated that the association rate constant between LF and NR was 5.00 × 10⁴ M^-1 s^-1, while the dissociation rate of the complex was 0.36 s^-1, at 25 °C. The stable complex predominated over free molecules (ΔG_25°C⁰=-29.35 kJ mol^-1), and the binding constant was 1.39 × 10⁵ M^-1, at 25 °C. The association of LF and NR to form an intermediate complex occurred in multi-steps. Nevertheless, the intermediate complex formation from the dissociation of the stable complex occurred in a single step with the activation energy independent of temperature. This study provides an important basis to explore LF as a vehicle for bioactive molecules.