Fig. 10

Interaction between a single ubiquitin and a citrate-coated silver nanoparticles. a TEM images of silver nanoparticles (left panel) and silver nanoparticles-ubiquitin coronas (right panel) where the associations of the silver nanoparticles and the proteins (shaded regions) are evident to imply their good binding affinity. b UV–vis absorbance of silver nanoparticles, ubiquitin, and silver nanoparticles–ubiquitin, featuring a red-shift of the absorbance peaks for silver nanoparticles–ubiquitin and silver nanoparticles alone due to dampened surface plasmon resonance. c Initial (t = 0 ns) and final (t = 50 ns) structure of the ubiquitin–citrate–silver nanoparticles complex system. Ubiquitin is represented as cartoons, the side chains as lines, and the citrates as sticks. The gray sphere represents the nanoparticle, and the charged atoms on the silver nanoparticles surface are shown as blue spheres. The zoom-in view of the final structure indicates the binding between the ubiquitin and a charged silver nanoparticles surface atom (modified from Ding et al. [83] by permission of The Royal Society of Chemistry)