Microtubules (MTs) are self-assembled proteinaceous filaments with nanometer scale diameters and micrometer scale lengths. Their aspect ratio, the reversibility of their assembly and their ability to be metallized by electroless plating make them good candidates to serve as templates for the fabrication of nanowires. We have shown that microtubule-associated-proteins (MAPs) play a critical role in maintaining the MT stability during Pt-catalyzed electroless Ni plating. MAP-stabilized MTs metallized for one minute in a Ni-acetate-based electroless-plating bath are coated with a metal film only several nanometers thick. The MAPs appear to lead to the formation of nanometer-wide metal bridges between the MTs. The metal coatings are constituted of small Pt clusters (similar to 3 nm), distributed and oriented randomly, embedded in an amorphous nickel matrix. (C) 2004 Kluwer Academic Publishers.