RESEARCH

Why do we focus on proteins?

Proteins are the products of genes, and thus are linear chains of the twenty natural aminoacids, each chain with its unique sequence defined by the originating gene and translated according to the genetic code. In physical terms proteins are heteropolymers with complex chemical properties and a high degree of internal flexibility (several degrees of freedom per aminoacid residue). But, most importantly, proteins are also sophisticated nanomachines that are in charge of most of the key biological functions in living cells.

The enzymes that catalyze all the metabolic reactions within the cell, the antibodies and interferons in charge of the defense against infection, the molecular messengers between cells and tissues, the photosystems I and II and the ATPase complex that compose the cellular energy plants, the cytoskeleton that sustains the cell’s shape and motion, the microtubules and kinesin motors that move nanoscale cargo from one cellular organelle to another; the factors that orchestrate the development of a fertilized egg into a full organism; they are all composed by proteins and protein assemblies. All such functions rely on a fundamental trait: the ability of proteins to exploit thermal energy to self-assemble into specific nanoscale 3D structures from the chemical blueprints encoded into their amino-acid sequence and change shape in response to stimuli.

In other words, the molecular basis for most cellular processes can ultimately be traced back to physical-chemical properties of the relevant proteins. This makes protein science and engineering a perfect arena for developing a truly quantitative and physical understanding of the fundamental processes that govern life and for implementing engineering strategies that exploit such knowledge for the design of myriads of nano-biotechnological applications, such as bioinspired materials, novel pharmaceuticals, improved catalysts and controllable nano devices.