Biology subjects

Petrotchenko, E. V.

Publications and source records attributed to Petrotchenko, E. V..

5 recordsLinked to original sources

bioRxiv2026

PHENOMS: Open-Source Software for Rust-Accelerated Hydrogen-Bond Analysis in Molecular Dynamics Simulations

Hydrogen-deuterium exchange mass spectrometry (HDX-MS) provides powerful insight into protein structure and dynamics, but interpretation of protection patterns at atomic resolution often requires complementary computational modeling. We present PHENOMS, an open-source Python package that integrates molecular dynamics trajectories with HDX-MS data to analyze backbone hydrogen-bond networks by tracking how individual hydrogen bonds and residue-residue contacts form, break, and reorganize throughout the simulations. This residue-level analysis can reveal local structural changes that may be missed by conventional global trajectory metrics. PHENOMS employs a multithreaded, Rust-accelerated computational engine that achieved an average 16-fold speedup (up to 100-fold) over widely used Python-based MD analysis packages in our benchmarks, while retaining individual hydrogen-bond resolution in every trajectory frame. We demonstrate PHENOMS through multiple retrospective case studies using published and in-house datasets, showing that it can recapitulate HDX-MS protection patterns, identify key residues that drive coordinated structural changes, and benchmark the computational efficiency of the approach. With automated quality-control workflows, PHENOMS provides a framework for integrating hydrogen-bond analysis with HDX-MS data or serves as a standalone, high-throughput tool for analyzing MD trajectories for broader applications in protein engineering, drug discovery, and structural biology.

biophysics↗

bioRxiv2026

Sex-dependent control of renal tubular homeostasis and stress tolerance by KDM6A

Biological sex is an important determinant of kidney disease susceptibility and outcomes. The epigenetic modifier KDM6A is an X chromosome-expressed lysine demethylase and molecular scaffold that escapes X chromosome inactivation. Here, we compared the effects of deletion of KDM6A from kidney tubule epithelial cells in female and male mice (KDM6ATubKO). Knockout of KDM6A from tubule cells aggravated kidney fibrosis caused by unilateral ureteral obstruction (UUO) in female mice, whereas male mice were unaffected by KDM6A absence. Unexpectedly, female (but not male) KDM6ATubKO mice developed spontaneous glucosuria that, when stressed by ligation of one ureter, presented as polyuria and a Fanconi renotubular syndrome-like picture affecting the unobstructed kidney. Absence of KDM6A from tubule epithelial cells of female mice caused mitochondrial circularization, tubule cell vacuolization with focal atrophy and lymphoid infiltration, and diminished sodium/glucose cotransporter 2 (SGLT2). Spatial transcriptomics and untargeted metabolomics revealed that knockout of KDM6A in female mice caused a shift in gene programs and metabolic pathways indicative of tubule cell metabolic dysfunction. In male mice, transcripts of the Y chromosome-expressed gametolog of Kdm6a, Uty were present in tubule epithelial cells at levels comparable to Kdm6a and they were upregulated with UUO. In summary, KDM6A is essential for normal tubule epithelial cell homeostasis in females but not in males. KDM6A and UTY are a dynamically regulated X-Y gene pair with at least partial compensatory overlap in function necessary for the preservation of kidney health and stress tolerance. Graphical abstract. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=145 SRC="FIGDIR/small/740137v1_ufig1.gif" ALT="Figure 1000"> View larger version (29K): org.highwire.dtl.DTLVardef@9186b8org.highwire.dtl.DTLVardef@23d4cborg.highwire.dtl.DTLVardef@67741eorg.highwire.dtl.DTLVardef@1f85dc7_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

bioRxiv2025

A Hit Prioritization Strategy for Compound Library Screening Using LiP-MS and Molecular Dynamics Simulations Applied to KRas G12D Inhibitors

An important step in screening small molecule libraries for drug discovery is hit prioritization and validation to rule out false positives, which is usually performed using biochemical and biophysical assays. The development of orthogonal assays that are highly sensitive and can accelerate the hit-to-lead process is valuable. Limited proteolysis combined with mass spectrometry (LiP-MS) is a technique used to study changes in protein structure upon ligand binding. In LiP-MS, proteins are exposed to low concentrations of proteases under native conditions. The resulting proteolytic pattern is sensitive to protein structure at the cleavage site, which can change upon ligand binding. We characterized the interaction of small molecule inhibitors of the KRas G12D mutant oncoprotein by LiP-MS combined with molecular dynamics (MD). Intact mass spectrometry and top-down analysis were used to detect and identify KRas G12D cleavage products in the presence and absence of inhibitors, thereby locating the cleavage sites in the protein. Cleavage sites protected upon compound binding correlated well with the switch II binding site. The degree of cleavage depends on binding affinity and the presence of specific functional groups in the inhibitors structure. A comparison of MD simulations for the ligand-free and ligand-bound proteins revealed the atomistic mechanisms by which the cleavage sites, located in flexible and disordered regions, are stabilized upon compound binding. We suggest that LiP-MS combined with MD (LiP-MS-MD) could be valuable in small molecule screening campaigns and add to the repertoire of available methods for high-quality hit selection in early-stage drug discovery.

biophysics↗

bioRxiv2025

Characterization of the KRas G12D-inhibitor interactions by HDX-MS and molecular dynamics simulations

Hydrogen-deuterium exchange (HDX) combined with mass spectrometry (MS) is a powerful technique for studying changes in protein structure and dynamics upon ligand binding. Protein-ligand complexes can result in increased protection of peptide-bond amides in HDX indicating protein structure stabilization. We have characterized the interaction of lead inhibitor candidates towards the KRas G12D oncoprotein by intact protein and bottom-up HDX-MS in combination with molecular dynamics (MD) simulations. Significant differences in HDX protection were detected upon inhibitor binding in the flexible switch-II pocket of the protein. We identified a correlation between ligand binding affinities and corresponding changes in protection. MD simulations of the free and inhibitor-bound KRas G12D proteins revealed changes in the hydrogen bond network of backbone amides in the switch-II region upon inhibitor binding, explaining the observed HDX protection. This combined HDX-MS and MD analysis approach provides a mechanistic picture of the KRas G12D protein-inhibitor interactions and may be a useful tool for future drug design efforts.

biophysics↗

bioRxiv2020

Mass Spectrometric detection of SARS-CoV-2 virus in scrapings of the epithelium of the nasopharynx of infected patients via Nucleocapsid N protein

Detection of viral RNA by PCR is currently the main diagnostic tool for COVID-19 [1]. The PCR-based test, however, shows limited sensitivity, especially at early and late stages of the disease development [2,3], and is relatively time consuming. Fast and reliable complementary methods for detecting the viral infection would be of help in the current pandemia conditions. Mass-spectrometry is one of such possibilities. We have developed a mass-spectrometry based method for the detection of the SARS CoV-2 virus in nasopharynx epithelial swabs, based on the detection of the viral nucleocapsid N protein. The N protein of the SARS-COV-2 virus, the most abundant protein in the virion, is the best candidate for mass-spectrometric detection of the infection, and MS-based detection of several peptides from the SARS-COoV-2 nucleoprotein has been reported earlier by the Sinz group [4]. Our approach shows confident identification of the N protein in patient samples even with the lowest viral loads and a much simpler preparation procedure. Our main protocol consists of virus inactivation by heating and adding of isopropanol, and tryptic digestion of the proteins sedimented from the swabs followed by MS analysis. A set of unique peptides, produced as a result of proteolysis of the nucleocapsid phosphoprotein of SARS-CoV-2, is detected. The obtained results can further be used to create fast parallel mass-spectrometric approaches for the detection of the virus in the nasopharyngeal mucosa, saliva, sputum and other physiological fluids.

molecular biology↗