Jorge Alegre-Cebollada

Current position: Postdoctoral fellow at Columbia University's department of biological sciences in New York

Education: Ph.D. in biochemistry from Complutense University, in Madrid, Spain, in 2008

Nonscientific interests: I love traveling and practicing yoga. Lately, I have been introduced to squash by some colleagues from the laboratory.

As an undergraduate student, I had the fortune to join Drs. Martínez del Pozo and Gavilanes' research group at Complutense University in Madrid, Spain. While in their group, I had the opportunity to learn many different techniques related to the field of protein biochemistry. I pursued my Ph.D., investigating the pore-forming activity of actinoporins, a group of toxins from sea anemones. After graduating, I moved to the U.S. and changed the focus of my research. Being able to manipulate single molecules fascinated me, so I was lucky enough that Dr. Julio M. Fernández accepted me in his lab at Columbia University in New York. The facts that chemical reactions are force dependent and that force-spectroscopy can be used to study their force dependency have attracted our attention ever since we first described the force-accelerated reduction of disulfide bonds by DTT. Now, enough knowledge has been gathered so that it seems possible to expand our methodology to other enzymatic activities, as we describe in this minireview.

Read Alegre-Cebollada's article on page 18961.

Raul Perez-Jimenez

Current position: Associate research scientist at Columbia University's department of biological sciences in New York

Education: Ph.D. in physical chemistry from the University of Granada, Spain, in 2005

Nonscientific interests: Musical composition and orchestral conducting, currently at The Juilliard School of Music in New York

I obtained my Ph.D. studying protein folding and using a variety of techniques, such as calorimetry, fluorescence, temperature jump and circular dichroism. However, as a student, I was fascinated by the emerging field of single-molecule biophisycs. The possibility of manipulating single protein molecules using atomic force microscopy captivated me, and, after graduating, I joined the lab of professor Julio M. Fernández at Columbia University. In Dr. Fernandez's lab, I had the opportunity to be a member of the pioneering team that developed assays based on the so-called force-clamp spectroscopy to study chemical reactions under force. The ability of force-clamp spectroscopy to monitor the rupture of individual covalent bonds has provided a wealth of information previously inaccessible with standard techniques. Perhaps the most significant use of force-clamp spectroscopy is the study of enzymatic reactions. This was first described in 2007, probing the chemistry of the enzyme thioredoxin. I consider these revolutionary studies the beginning of a new era in chemistry and biochemistry.

Read Perez-Jimenez's article on page 18961.

Pallav Kosuri

Current position: Ph.D. student at Columbia University's department of biochemistry and molecular biophysics

Education: B.S./M.S. in engineering physics in 2005 from the Royal Institute of Technology, in Stockholm, Sweden

Nonscientific interests: Documentary photography, travel and classical guitar

I completed my undergraduate studies in physics and biology at the Royal Institute of Technology and at Karolinska Institutet, respectively. I then conducted my master's thesis research at CERN, outside Geneva, Switzerland, where I developed a new laser ion source at a nuclear physics facility. The next year was spent traveling to various exotic places around the world while working as a documentary photographer for a major Swedish publishing agency. In 2006, after receiving a Fulbright Scholarship, I enrolled in a Ph.D. program at Columbia University. Joining the lab of Julio Fernández a year later, I am currently using force spectroscopy to dissect the chemical mechanisms of enzymes.

Read Kosuri's article on page 18961.

Julio M. Fernandez

Current position: Professor at Columbia University's department of biological sciences

Education: Ph.D. in physiology from the University of California, Los Angeles, in 1982

Nonscientific interests: I love music, reading and unscheduled traveling in remote places. I like to ski.

My earlier work was focused on the molecular mechanisms of exocytosis. However, the realization that the events leading to vesicle fusion are mechanical in nature led me to switch my efforts to study protein mechanics at the single-molecule level. Since 1997, I have concentrated my efforts on developing protein engineering and force-spectroscopy techniques to study the dynamics of single proteins under force. This has been a fertile new field of study, allowing us to develop new ideas and techniques and change the way we view protein dynamics. For example, force-quench techniques to monitor protein-folding reactions uncovered a rich diversity of folding trajectories that had been hidden in bulk experiments. We recently have applied these techniques to study the effect of force on chemical reactions. (For example, capturing the rotation and elongation of single disulfide bonds as they reach the transition state during bimolecular chemical reactions.) I look forward to doing much more with this new form of protein spectroscopy in the coming years.

Read Fernandez's article on page 18961.