Protein-based self-assembled nanomaterials are arousing more and more interest due to their attractive biocompatibility.Stable Protein 1(SP1),due to its exceptionally thermal and chemical stability to harsh conditions,becomes an ideal building block for nanomaterials.[1] The self-assembled protein nanotubes achieved through engineering ring-shaped SP1 has been confirmed by atomic force microscopy.Here,we trace dynamic self-assembly process of SP1-based nanotubes by coarse-grained MARTINI force field simulation.[2] It reveals that the electrostatic interactions between oppositely surface-charged protein rings are dominant in driving the self-assembly to form nanotubular structures.The present results show that SP1 could self-assembly into nanotubes in mild conditions within 8 μs simulation duration,and it is potential to serve as a novel and underlying building block of various nanotubes.It is also confirmed that MARTINI polarizable water model could account for the electrostatic interactions well,as opposed to standard MARTINI water model.[3] It demonstrates that coarse-grained simulation could serve as an efficient tool to probe and trace dynamic self-assembly process and mechanism of nanostructures.It paves the way for the design of desirable self-assembled protein-based nanomaterials.