Characterization of Glucosamine and Collagen crystallization by terahertz time-domain spectroscopy

Terahertz time-domain spectroscopy (THz-TDS) has been demonstrated as a promising solid-state analytical tool which can probe intermolecular interactions through crystal lattice vibrations. However, the current studies commonly investigate the interactions between two biological or pharmaceutical molecules with relatively low molecular weights. The interaction between small biomolecule and biomacromolecule in the crystallization process has not been reported. In this study, THz-TDS was used as a novel technique to characterize the interaction between small biomolecule (Glucosamine) and biomacromolecule (Collagen) in the crystallization process. The absence of THz absorption peak in solvent mixed sample with weight ratio of 1:1 showed the crystallization process of glucosamine was disturbed by collagen. The recurrence of THz absorption peak in solvent mixed sample with weight ratio of 7:1 may be related to the saturation of interaction between glucosamine and collagen. The dissolving and lyophilizing processes were validated to hardly affect the crystal formation of glucosamine. This study further demonstrates THZ-TDS has the capability to characterize the interaction between small biomolecule and biomacromolecule in solid-state.