Subject
At the Laboratory of Physicochemistry of Infectious Diseases, we are dedicated to elucidating the mechanisms of action and molecular evolution of proteins by which bacterial cell homeostasis is maintained, seeking to contribute to the design of new antibiotics that intensify the host's efforts to disrupt pathogens.
We seek to develop methodologies able to provide experimental and quantitative information on protein internal dynamics that are fundamental to the biological function. Our working hypothesis is that biological function is determined both by the structure of proteins and by their internal dynamics, therefore we hope that our methodologies will further the understanding of the mechanisms employed by molecular evolution.

Approach
In the lab we work with different organic and inorganic RSS, some of them synthesized in situ. By incubating these chemical species with the proteins studied, we can identify any covalent modifications that took place by mass spectrometry experiments. Moreover, we evaluate the effect of these modifications in protein-DNA affinity and subjacent thermodynamic parameters with fluorescence anisotropy experiments together with calorimetric measurements.

Advances
Molecular evolution of transcriptional regulators in pathogenic bacteria
Successful human pathogens evade our immune system through the expression of “resistance genes” modulated by transcription factors that are able to sense the stress induced by the system’s immune response or antibiotics. This project is centered around the understanding of the most fundamental biophysical mechanisms behind the sensing and the genetic regulation key to bacterial resistance.
Novel strategies for determining entropic contributions to ligand binding harnessing transcription factors as model systems
Protein dynamics and its hydration layer play a fundamental role in biological function (associated with the ΔG). Nevertheless, the available experimental tools to quantify the magnitude of the contribution of dynamics to protein function (linked to ΔS) are still quite restrictive compared to the tools employed to resolve protein structures (linked to ΔH). Thus, even if a consensus has been reached that they play an essential role in protein function, their contribution to  the evolution of novel functions is still under debate.
Reactive Sulfur species homeostasis as an alternative therapy in the face of resistant pathogens.
Recent studies have shown that H2S and reactive sulfur species (RSS) improve bacterial survival in the face of ROS/RNS from the immune response and antibiotic induced oxidative stress. The success of a pathogen relies on the expression of specialized transcription factors that can sense these species and modulate a transcriptional response to maintain RSS homeostasis and prevent cellular toxicity. This line of work centers around the comprehension of the regulating mechanisms of RSS/H2S homeostasis and how this could help improve antimicrobial strategies against resistant strains. Our model organisms are prioritary human pathogens as Acinetobacter baumannii and Vibrio cholerae. 
Portable sensors of chemical contaminants in the Matanza-Riachuelo basin
The monitoring of heavy metals in waters is essential for the detection of these contaminants in consumption water and alert the affected population. Nonetheless, the required equipment is specific, expensive and not transportable, greatly limiting the number of controls that can be done. In that sense, this project aims to develop a low-cost, portable device for the detection of heavy metal contaminants on site and without previous training required. The device is based on in vitro transcription assays that employ bacterial proteins to regulate the production of a fluorescent molecule in presence of a given contaminant above specific concentration and only requires an economic illumination device to put forward the presence of contaminants in the sample. This technology, called ROSALIND, has been developed by an interdisciplinary work group that combines the fundamental areas of bioinorganic and bioengineering with environmental monitoring.