Biology subjects

Fuenzalida Werner, J. P.

Publications and source records attributed to Fuenzalida Werner, J. P..

3 recordsLinked to original sources

bioRxiv2023

Supercharged Fluorescent Protein-Apoferritin Cocrystals for Lighting Applications

The design of lighting sources based on fluorescent proteins (FPs) has been limited by the lack of protocols to stabilize FPs under preparation (deposition techniques, organic solvents, etc.) and working (temperature, irradiation, etc.) conditions. As a critical bottleneck, photo-induced heat generation due to FP motion and quick heat transfer leads to working device temperatures of ca. 70 {degrees}C, resulting in a quick FP-denaturation and, in turn, a quick loss of the device performance. Herein, we showcase FP stabilization for lighting devices with an electrostatically self-assembled FP-apoferritin cocrystals embedded in a silicone-based color down-converting filter. This strategy highlights three major advances: i) engineering of positively supercharged FPs (+22) without losing photoluminescence and thermal stability compared to its native form, ii) a crystallization protocol resulting in highly emissive cocrystals keeping the photoluminescence features of the FPs, and iii) a 40-fold increase of the lighting device stability compared to reference devices due to the reduction of the device working temperatures to 40 {degrees}C. Thus, the success of this multidisciplinary approach contributes toward developing stable energy-related protein-based optoelectronics.

bioengineering↗

bioRxiv2020

Challenging a preconception: Optoacoustic spectrum differs from the absorption spectrum of proteins and dyes for molecular imaging

Optoacoustic (photoacoustic) imaging has seen marked technological advances in detection and data analysis, but there is less progress in understanding the photophysics of optoacoustic signal generation of commonly used contrast agents, such as dyes and chromoproteins. This gap blocks the precise development of novel agents and the accurate analysis and interpretation of Multispectral Optoacoustic Tomography (MSOT) images. To close it, we developed a multimodal laser spectrometer (MLS) to enable the simultaneous measurement of optoacoustic, absorbance, and fluorescence spectra. MLS provides reproducible, high-quality optoacoustic (non-radiative) spectra by using correction and referencing workflow. Herein, we employ MLS to analyze several common dyes (Methylene Blue, Rhodamine 800, Alexa Fluor 750, IRDye 800CW and Indocyanine green) and proteins (sfGFP, mCherry, mKate, HcRed, iRFP720 and smURFP) and shed light on their internal conversion properties. Our data shows that the optical absorption spectra do not correlate with the optoacoustic spectra for the majority of the analytes. We determine that for dyes, the transition underlying the high energy shoulder, which mostly correlates with an aggregation state of the dyes, has significantly more optoacoustic signal generation efficiency than the monomer transition. Our analyses for proteins point to a favored vibrational relaxation and optoacoustic signal generation that stems from the neutral or zwitterionic chromophores. We were able to crystalize HcRed in its optoacoustic state, confirming the change isomerization respect to its fluorescence state. Such data is highly relevant for the engineering of tailored contrast agents for optoacoustic imaging. Furthermore, discrepancies between absorption and optoacoustic spectra underline the importance of correct spectral information as a prerequisite for the spectral-unmixing schemes that are often required for in vivo imaging. Finally, optoacoustic spectra of some of the most commonly used proteins and dyes in optical imaging, recorded on our MLS, reveal previously unknown photophysical characteristics, such as unobserved photo-switching behavior.

biophysics↗

bioRxiv2019

Protein-surfactant-polysaccharide nanoparticles increase the catalytic activity of an engineered β-lactamase maltose-activated switch enzyme

We present polysaccharide-based nanoparticles able to associate and increase the catalytic activity of the maltose-binding MBP317-347 switch enzyme. Fluorescence quenching and molecular docking studies along with the partial resistance to increasing pH and ionic strength indicate that the increase in enzymatic activity is due to a specific interaction between the maltose binding pocket on MBP317-347 and alginate exposed on the surface of the nanoparticles. Finally, we show that the hybrid self co-assembled particles increase the half-life of MBP317-347 over six-fold at 37{degrees}C, thus reflecting their potential use as a macromolecular drug delivery system.

biochemistry↗