Heterozygous mutations or genetic variants in the GBA1 gene, which encodes for the β-glucocerebrosidase (GCase), a lysosomal hydrolase enzyme, may increase the risk of Parkinson’s disease (PD) onset. The heterozygous E326K form is one of the most common genetic risk factors for PD worldwide, but, to date, the underlying molecular mechanisms remain unclear. Here, we investigate the effect of the E326K on the structure, stability, dimerization process, and interaction mode with some proteins of the interactome of GCase using multiple molecular dynamics (MD) simulations at pH 5.5 and pH 7.0 to mimic the lysosomal and endoplasmic reticulum environments, respectively. The analysis of the MD trajectories highlights that the E326K mutation did not significantly alter the structural conformation of the catalytic dyad but significantly makes the structure of the dimeric complexes unstable, especially at lysosomal pH, potentially impacting the organization of the quaternary structure. Furthermore, the E326K mutation significantly impacts protein interactions by altering the binding mode with the activator Saposin C (SapC), reducing the binding affinity with the inhibitor α-Synuclein (α-Syn), and increasing the affinity for the Lysosomal integral membrane protein-2 (LIMP-2) transporter.

Cancer remains a leading cause of death worldwide, highlighting the urgent need for novel and more effective treatments. Natural products, with their structural diversity, represent a valuable source for the discovery of anticancer compounds. In this study, we screened 750 Antarctic extracts to identify potential inhibitors of human topoisomerase 1 (hTOP1), a key enzyme in DNA replication and repair, and a target of cancer therapies. Bioassay-guided fractionation led to the identification of palmitic acid (PA) as the active compound from the Antarctic sponge Artemisina plumosa, selectively inhibiting hTOP1. Our results demonstrate that PA irreversibly blocks hTOP1-mediated DNA relaxation and specifically inhibits the DNA religation step of the enzyme’s catalytic cycle. Unlike other fatty acids, PA exhibited unique specificity, which we confirmed through comparisons with linoleic acid. Molecular dynamics simulations and binding assays further suggest that PA interacts with hTOP1-DNA complexes, enhancing the inhibitory effect in the presence of camptothecin (CPT). These findings identify PA as a hTOP1 inhibitor with potential therapeutic implications, offering a distinct mechanism of action that could complement existing cancer therapies.

The RNA-binding protein HuR (embryonic lethal abnormal vision-like protein 1) regulates mRNA stability and translation. HuR contains three RNA-recognition motifs (RRMs): the RRM1 and RRM2 confer high-affinity mRNA binding, while RRM3 mediates protein oligomerization. Although HuR is predominantly nuclear, cellular stimuli trigger its cytoplasmic translocation via a nucleocytoplasmic shuttling sequence between the RRM2 and RRM3 domains. Despite HuR's critical role in post-transcriptional gene regulation, its full-length three-dimensional (3D) structure remains uncharacterized. In this study, we employed an in silico approach, combining molecular modeling, atomistic, and coarse-grained molecular dynamics simulations to build and validate a 3D model of the full-length HuR in complex with an mRNA fragment. Structural analysis of the model identified a tyrosine residue as a key mediator of HuR-RNA interaction stability and provided novel structural insights into HuR's RNA-binding mechanism, contributing to a deeper understanding of its regulatory functions.

Desert strains of the genus Chroococcidiopsis are among the most desiccation-resistant cyanobacteria capable of anhydrobiosis. The accumulation of two sugars, sucrose and trehalose, facilitates the entrance of anhydrobiotes into a reversible state of dormancy by stabilizing cellular components upon water removal. This study aimed to evaluate, at the atomistic level, the role of trehalose in desiccation resistance by using as a model system the 30S ribosomal subunit of the desert cyanobacterium Chroococcidiopsis sp. 029. Molecular dynamic simulations provided atomistic evidence regarding its protective role on the 30S molecular structure. Trehalose forms an enveloping shell around the ribosomal subunit and stabilizes the structures through a network of direct interactions. The simulation confirmed that trehalose actively interacts with the 30S ribosomal subunit and that, by replacing water molecules, it ensures ribosomal structural integrity during desiccation, thus enabling protein synthesis to be carried out upon rehydration.

Activation of the reverse transsulfuration pathway contributes to the survival and persistence of multidrug-resistant bacteria. The first step of this pathway, catalyzed by the enzyme cystathionine β-synthase (CBS), plays a crucial role in maintaining redox balance and cysteine homeostasis, making it an attractive therapeutic target against multidrug-resistant infections. In this study, we demonstrate that both Pseudomonas aeruginosa CBS and Klebsiella pneumoniae CBS exhibit high responsiveness to the allosteric activator S-adenosylmethionine (SAM) and preferentially utilize O-acetylserine (OAS) as a substrate over serine. The crystal structure of PaCBS and the AlphaFold-2 model of KpCBS reveal a novel domain organization characterized by an inverted arrangement of the regulatory Bateman module relative to the catalytic core. These findings provide a new structural and functional basis for the selective inhibition of CBS in multidrug-resistant pathogens.