First-principles study of the electronic and molecular structure of protein nanotubes - art. no. 115425

The electronic and molecular structures of protein nanotubes (PNT's) have b een investigated theoretically by first-principles electronic structure cal culations. The results have been discussed in comparison to those of the po lypeptide open chains (POC's) and polypeptide closed rings (PCR's) in order to give a systematic understanding. Focusing on the intra-ring and inter-r ing hydrogen bonds (HB's), we also investigate the PCR stacking mechanism. The present calculation reveals that PNT's are semiconductors and that an e xtra proton in the tube interior has the potential to be an electron accept or.