Aarat P. Kalra | Harnessing Protein Polymers for Nanotechnology and Medicine
Publications
I work on the interface of physical chemistry and biology, focussing on microtubule bioelectricity. I enjoy writing papers, and there will typically be a few in the works whenever you meet me. I collaborate with experts from physics, cell biology, neuroscience, materials science and chemistry. Drop me an email if you have an idea!
This list shows publications in which I led the research i.e. where I was either the first or co-first author. For a complete list of papers, visit my Google Scholar page
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Electronic Energy Migration in Microtubules
ACS Central Science
We showed that energy can migrate by diffusive energy transfer over unexpectedly large distances (6.6 nm) in microtubules. We found that conventional Förster theory predicts a diffusion length of only ~1.5 nm; insufficient to explain our observations. Introducing the anesthetics etomidate and isoflurane decreased the observed energy diffusion length. We concluded that it is worth considering protein assemblies, like microtubules, for ultraviolet light-harvesting systems.
A Nanometric Probe of the Local Proton Concentration in Microtubule-Based Biophysical Systems
Nano Letters
We used a double functional fluorophore to understand how microtubules alter the electrostatic environment in their immediate vicinity. Our probe showed that they lowered their local pH value by 'one unit' when the solution of the rest of the solution was in the physiological range. To the best of my knowledge, these findings provide first experimental validation to models showing the electrostatically nontrivial roles of microtubules in the cell.
All Wired Up: An Exploration of the Electrical Properties of Microtubules and Tubulin
ACS Nano
We reviewed the electrical (ionic) properties of microtubules and tubulin. We examined papers showing how microtubules respond to electric fields, and reviewed various modes of ionic transport and communication through these polymers. Looking forward, we discussed medical applications and fundamental open questions for microtubule bioelectricity.
Revealing and Attenuating the Electrostatic Properties of Tubulin and Its Polymers
Wiley Small
Here, we showed that the electrostatic charge of tubulin could be tuned from being highly negative in physiological conditions to being positive in DMSO. Also, the charge of tubulin dictated that morphology of the polymer that it would stabilize -- form microtubules (cylidrical) when tubulin is negative, to sheets and aggregates when tubulin is positive.
Investigation of the Electrical Properties of Microtubule Ensembles under Cell-Like Conditions
MDPI Nanomaterials
We determined the capacitance and resistance of microtubule networks in cell-like conditions. We found that while the addition of microtubules appreciably altered solution capacitance, the addition of unpolymerized tubulin did not. The paper was the first to explore the electrical properties of microtubules in these conditions.
Melanin-Based Electronics: From Proton Conductors to Photovoltaics and Beyond
Biosensors and Bioelectronics
The successful interfacing of electronics with biology is the next frontier for microelectronics and nano- technology. Melanin, a naturally occurring conjugated polymer composed of different structural subunits, may be an ideal candidate for such interfacing. In this paper, we reviewed the status of melanin towards achieving biocompatible electronics.