▎ 摘　　要

Structural analysis of proteins using X-ray crystallography is crucial for discovering their biochemical functionalities. However, growing X-ray-quality crystals of proteins is often a challenging task that requires complicated and tedious processes, especially for the formation of crystalline seeds in the early stage of the process. In the present study, graphene quantum dots (GQDs) were investigated as a nanomaterial nucleant for protein crystallization in the aspects of the process accelerations and their possible underlying mechanisms, where lysozyme was employed for a model system. Compared to that without GQDs, dramatically faster formation of crystalline seeds was observed in the presence of GQDs within 2 h of incubation. The hydrodynamic size of lysozyme increased by about 30% when GQDs were included according to dynamic light scattering measurements, implying a possible binding of GQDs to the protein. X-ray diffraction analysis of lysozyme crystals also implies the possible binding of GQDs to the protein by showing reduced thermal B-factors when GQDs were included, suggesting flexibility reducing interactions of GQDs with random coil sites. In spite of the prevalent existence of GQDs in the crystal, the X-ray structural analysis cell parameters of lysozyme grown with GQDs showed negligible differences compared to those grown without GQDs, suggesting that GQDs might be an ideal nucleant for protein crystallization.