ABSTRACT
Proteins and peptides serve as the major molecular sca old material of the biological world. An example of nanoscale elements is
the self-assembled actin cytoskeleton, the molecular structures that give the cell its physical rigidity, and the self-assembled microtubules that serve as nanoscopic protein railways that enable the transport of “cargo” within the cell using nanoscale protein motors. Proteins also serve as the building blocks for macroscopic structural elements, for instance, the collagen proteins in the skin and the keratin proteins in nails and hair. In addition, proteins serve as the building blocks for elaborate structures possessing unique physical properties such as silk, whose tensile strength-to-density ratio is about ve times higher than steel. e formation of inorganic biological structures such as bones, teeth, and marine animal shells is directed by protein templates via the speci c interaction of proteins and peptides with calcium or silicon (Naik et al. 2002).
