Electrical mapping of microtubular structures by surface potential microscopy

Abstract

Microtubules sMTsd are important cytoskeletal polymers that play an essential role in cell division and transport in all eukaryotes and information processing in neurons. MTs are highly charged polyelectrolytes, composed of hollow cylindrical arrangements of ab-tubulin dimers. To date, there is little information about electrical properties of MTs. Here, we deposited and dried MTs onto a gold-plated surface to image their topology by atomic force microscopy sAFMd, and determined their electrical mapping with surface potential microscopy sSPMd. We found a strong linear correlation between the magnitude of relative surface potential and MT parameters, including diameter and height. AFM images confirmed the cylindrical topology of microtubular structures, and the presence of topological discontinuities along their surface, which may contribute to their unique electrical properties.