Nucleoprotein Assemblies

Bionanotechnology is an emerging field with great promise in molecular science. The field is so new that it has yet to be formally defined. However, it can be characterized as a primitive technology that takes advantage of the properties of highly evolved natural products like nucleic acids and proteins by attempting to harness them to achieve new and useful functionalities on the nanoscale. It is appropriate to compare bionanotechnology to the technology of the paleolithic in which natural products like wood and stone were shaped into implements and devices. Much like the paleolithic technologists who used knowledge of their surroundings to identify components and processes used in tool-making, modern bionanotechnologists use knowledge of chemistry, biochemistry, and molecular biology to identify components and processes for the construction of self-assembling materials and devices. Paleolithic technology was limited by the basic properties of natural products like wood and stone. Wood and stone could be shaped and modified, but they could not be forced into the arbitrary de novo designs that can be attained with our modern understanding of wood composites and ceramics. In a like fashion, bionanotechnology is limited by the basic properties of biomolecules. The field will certainly mature in the near future, but this maturation will require, among other things, advances in our understanding of the nature of nucleic acid and protein folding so that arbitrary de novo design of such molecules can be contemplated. Like other forms of nanotechnology, bionanotechnology seeks to define approaches to the fabrication of useful materials and devices. However, the construction principles utilized in the field often originate in biology and the goals are often biomemetic (e.g., the construction of biosensors [1]) or aimed at the solution of long-standing research problems (e.g., protein crystallization [2]. Nonbiological problems have also been approached in attempts at the construction of electronic circuitry using biomolecules [3] and the construction of a fuelled nanomechanical oscillator [4] and a nanomechanical switch [5). At the heart of these approaches is the concept of self-assembly. Selfassembly of ordered elements is a defining property of living things. Moreover, the progressive increase in the complexity of the processes used by living things in self-assembly is a defining property of evolution. During the roughly 4.2 billion years of prebiotic and Darwinian evolution that have taken place on earth, an almost incomprehensible variety of molecular structures, functionalities, and associations have appeared. This evolutionary experience is stored in modern living systems. For this reason, modern living systems comprise a wealth of addressable macromolecular components. Of these, the nucleic acids and proteins are the most easily manipulated and the best understood. Thus, it is not surprising that they have been the first to be exploited to produce nucleoprotein-based addressing systems in nanobiotechnology [6–11] that attempt to exploit self-assembly and ordered proximity.