Biology subjects

Burastero, O.

Publications and source records attributed to Burastero, O..

4 recordsLinked to original sources

bioRxiv2026

Global analysis of thermal and chemical denaturation using CheMelt: Thermodynamic dissection of highly thermostable de novo designed proteins

De novo protein design often produces thermostable proteins that denature above 100 {degrees}C, which complicates the analysis of their stability. Thermostable proteins can be unfolded by combined chemical and thermal denaturation followed by global analysis of multiple melting curves. Here, we have developed CheMelt, a new online tool for global analysis of unfolding data via an intuitive graphical user interface. We use nanoscale differential scanning fluorimetry followed by CheMelt data analysis to dissect the combined thermal and chemical denaturation of thirty-five de novo designed protein binders. Thirteen present sufficient fluorescence changes to extract thermodynamic parameters of unfolding. These de novo designed proteins have systematically lower {Delta}Cp and m-values than comparable natural proteins. We show that a high thermostability of a designed protein does not necessarily imply a high equilibrium stability, and demonstrate the potential of CheMelt in dissecting thermodynamic properties for protein design and engineering. CheMelt can be accessed at https://spc.embl-hamburg.de/app/chemelt

biophysics↗

bioRxiv2025

ChiraKit, an online tool for the analysis of circular dichroism spectroscopy data

Circular dichroism (CD) spectroscopy is an established biophysical technique to study chiral molecules. CD allows investigating conformational changes under varying experimental conditions and has been used to understand secondary structure, folding and binding of proteins and nucleic acids. Here, we present ChiraKit, a user-friendly, online, open-source tool to process raw CD data and perform advanced analysis. ChiraKit features include the calculation of protein secondary structure with the SELCON3 and SESCA algorithms, estimation of peptide helicity using the helix-ensemble model, the fitting of thermal/chemical unfolding or user-defined models, and the decomposition of spectra through singular value decomposition (SVD) or principal component analysis (PCA). ChiraKit can be accessed at https://spc.embl-hamburg.de/.

biophysics↗

bioRxiv2024

Subtleties in Clathrin Heavy Chain Binding Boxes provide selectivity among Adaptor Proteins of Budding Yeast

Clathrin, forming the triskelion network, orchestrates highly regulated cellular processes facilitating cargo internalization and trafficking in eukaryotes, with its N-terminal domain (NTD) pivotal for adaptor protein (AP) interactions. The NTD contains up to four AP-binding sites, and their roles in preferential occupancy by APs have not been addressed. Here, employing a combination of integrative biophysical and structural approaches together with in vivo functional experiments, we investigated the binding hierarchy and selectivity of adaptors for clathrin, aiming to understand the evolutionary conservation of redundant APs and their specialized roles in endocytosis and cellular trafficking mechanisms. We found that yeast epsin Ent5 displayed the highest affinity for clathrin, indicating its significant role in cellular trafficking processes. Epsins Ent1 and Ent2, which are crucial for endocytosis but described to have redundant functions, revealed distinct binding patterns; Ent1 demonstrated stronger interactions with clathrin than Ent2, explaining its functional divergence towards actin binding. Despite both having actin anchoring domains, since Ent1 is actually more stably recruited by clathrin, it would provide a better actin anchoring function. These results offer molecular insights into AP selectivity, suggesting they competitively bind clathrin while also targeting different clathrin sites.

molecular biology↗

bioRxiv2023

Raynals, an online tool for the analysis of dynamic light scattering

Dynamic light scattering (DLS) is routinely employed to assess the homogeneity and size distribution profile of samples containing microscopic particles in suspension or solubilised polymers. In this work, we introduce Raynals, an user-friendly software for the analysis of single-angle DLS data that uses the Tikhonov-Phillips regularisation. Performance is evaluated on simulated and experimental data, generated by different DLS instruments, for several proteins and gold nanoparticles. DLS data can be easily misinterpreted and the simulation tools available in Raynals allow understanding of the limitations of the measurement and its resolution. It has been designed as a tool to address quality control of biological samples, during sample preparation and optimisation, and it helps in the detection of aggregates showing the influence of large particles. Last, Raynals provides flexibility in the way the data is presented, allows exporting publication-quality figures, it is free for academic use, and can be accessed online on the eSPC data analysis platform at spc.embl-hamburg.de.

biophysics↗