I obtained my B.Sc. degree in Chemical Engineering from Gh. Asachi Technical University (Iasi, Romania), as head of his class (out of 250 students). I did my Ph.D. at University of Geneva (Switzerland), in the area of Physical and Analytical Chemistry, with focus on colloids, polymers and surface chemistry. There I conducted research under the supervision of prof. Michal Borkovec using the Atomic Force Microscope (AFM) to measure interaction forces in colloidal probe and single molecule force spectroscopy modes and to prepare and characterize nano-patterned surfaces. The main subject of my Ph.D. was to measure and understand the interactions appearing between heterogeneously charged surfaces using force applying techniques, such as AFM . During my Ph.D. I was awarded for my research with the SCS-Mettler-Toledo-Prize, given by the Swiss Chemical Society at the SCS Fallmeeting (Zürich, Switzerland, 2008) and I was selected to participate to the 59th Lindau Nobel Laureates Meeting, between Nobel Laureates and International Best Talents (Lindau, Germany, 2009). For my post-graduate research training I moved to Columbia University, in the lab of prof. Julio M. Fernandez, in the Biological Sciences Department. In my first year in Fernandez lab I have studied thermal effects on the mechanical unforlding of polyproteins. For this I have developed a setup capable of conducting force-clamp spectroscopy under controlled temperature conditions. I am currently involved in a research project aiming at determining the molecular mechanisms that control protein extensibility using a combination of magnetic tweezers and Total Internal Reflection Fluorescence (TIRF).

I obtained my PhD from Complutense University (Madrid, Spain) in 2008. I developed my research under the supervision of Drs. Á. Martínez del Pozo and J. G. Gavilanes, at the Department of Biochemistry and Molecular Biology I. I studied the mechanism of pore formation by a family of eukaryotic pore-forming toxins, the actinoporins from sea anemones. We employed a variety of biochemical and biophysical approaches to understand how actinoporins interact with lipid membranes and the subsequent conformational changes they experience.

In May 2008 I joined Julio Fernandez lab. Since then, I have been subdued by the new possibilities single-molecule techniques offer to biologists. I have been involved in projects dealing with protein mechanics, such as the realization that intramolecular isopeptide bonds in adhesins of gram-positive bacteria confer unprecedented mechanical stability to protein domains. We have also implemented an assay based on mechanical uncaging of cysteine residues that allowed us to monitor in real-time the isomerization of disulfide bonds in proteins. My current research projects try to bridge the gap between Protein Mechanics and Biology. I want to know how the mechanical properties of proteins determine the macroscopic behavior of tissues and cells. Pili from Gram-positive bacteria are natural polyproteins that have to overcome high mechanical stress in vivo. Using force-spectroscopy, we can dissect the mechanical properties of pili components. We are trying to understand how mechanically defective pili are challenged when adhering under mechanical stress. Our strategy may be useful to design new antibiotics that interfere with the attachment of pathogenic bacteria.

I obtained my Ph.D. degree in Physical Chemistry from the University of Granada under the supervision of Dr. Jose M. Sanchez-Ruiz and Dr. Beatriz Ibarra-Molero. My thesis work focused mainly in an attempt to define the role of surface charge interactions in protein stability as well as the study of the evolutive information obtained from sequence alignments and its consequences in protein folding, structure and stability. My interest now is focused in the study of the protein folding as well as the mechanical stability using Single Molecule Force Spectroscopy. The techniques developed in Dr. Fernandez's Lab have become a powerful tool for the study of protein folding/unfolding processes under a stretching force in a new manner that reveals features of proteins non accessible with bulk techniques. I am interested in the use of the Force-clamp techniques to understand how a protein finds the way to fold into a native state and what are the more important aspects involved.

I am a second year PhD student in the Biochemistry and Molecular Biophysics program at Columbia. I received my undergraduate degree in 2011 from the University of Southern California, where I worked in the lab of Dr. Mohamed El-Naggar. My research there focused on microbial fuel cells and bacterial extracellular electron transfer. I joined the Fernandez lab in January 2012. My research interests primarily consist of the effects of mutations or oxidative cysteine adducts on the mechanical stability and refolding kinetics of titin, a large elastic protein found in all types of muscle. Through a collaboration with Dr. Lawrence Shapiro in the Biochemistry department at Columbia, I’ve been working to obtain crystal structures of various modified titin domains. My aim is to provide a quantitative structural basis to accompany the results of the force spectroscopy experiments obtained by my colleagues. My goals are to advance the understanding of the interplay between structure and mechanical stability, and to shed light on the molecular mechanisms of cardiomyopathy, infarction, and other heart disorders.

Jason Feng is an undergraduate student at Columbia College and a summer undergraduate research fellow currently pursuing a B.A. in mathematics/philosophy.

Jason is working on detecting the pKa of small molecules as they interact with protein substrates on a single molecule level via atomic force microscopy.

In his spare time, Jason enjoys table tennis, bonsai, and considering the meaning of existence.

Molecular Biologist and lab manager

I am in charge of the molecular biology section of the laboratory. I engineer most of the polyproteins that we use. We have a well established protocol for constructing polyproteins at the DNA level and then expressing them in bacteria. I use Talon columns and FPLC for protein purification. We struggle a bit with engineering AFM ready polyproteins. Not all of them give nice pulls. If so, I am the one that usually gets to re-engineer and/or re-express the proteins. I teach all the lab members how to do it and also I am happy to help other investigators by phone and email. I welcome inquiries.