The invention of the atomic force microscope (AFM) in 1986 by Binnig, Quate and Gerber (Phys. Rev. Lett. 56, 930) started a revolution in many branches of science by realizing an unprecedented possibility to visualize and manipulate individual molecules under ambient conditions including water, which is critical for most studies involving bio-molecules. Biomolecular studies are therefore, in my opinion one of the main beneficiaries of this seminal invention. I was very fortunate to start my AFM research in 1997, the year, which marked great progress in AFM-based single-molecule force spectroscopy of proteins and polysaccharides. From the very beginning of my AFM work I experienced a particular appeal to polysaccharides research. This is because the wealth of information contained in their AFM measured force-extension relationships with totally unanticipated deviations from the entropic elasticity of simple polymers prompted me to believe that many interesting and quite fundamental observations can soon be made by studying polysaccharides elasticity. Protein mechanics is, in my opinion, another area of great potential because investigating the elastic properties of individual proteins promises to make significant contributions to the understanding of elasticity of various intra- and extra-cellular structures and of adhesion and mechanotransduction. In addition, investigating mechanical unfolding and refolding reactions of individual proteins under "vectorial" condition can contribute to elucidating the mechanism of protein folding in vitro and in vivo (co-translational folding), which is fundamental to all biology.
More recently we initiated a new area of research by applying the AFM-based technology to study DNA mechanics, damage and repair. While the polysaccharide and protein research is extremely rewarding by continuously offering quite fundamental observations and discoveries to be made, the DNA research promises, in addition, even a greater scientific fulfillment through its possible contributions to medicine and human health. This new "DNA direction" has already proved quite successful. Our (Ke, Humeniuk, S-Gracz, Marszalek) 2007 paper in Physical Review Letters "Direct Measurements of Base Stacking Interactions in DNA by Single Molecule Atomic Force Spectroscopy" was selected by APS News, a publication of the American Physical Society, as one of the 36 most interesting works in Physics in 2007.
-Piotr E. Marszalek
For an overview of our research and research in the field, see our recently published reviews: