Staphylococcus aureus is a major pathogen responsible for severe and persistent infections, particularly due to its ability to form biofilms—structured communities of bacteria encased in an extracellular matrix that confers resistance to antibiotics and host immune defenses. Central to this virulence is the production of functional amyloids, specifically phenol-soluble modulin α1 (PSMa1), which acts as a key structural scaffold in the biofilm matrix. This study investigates the potential of molecular tweezers, a class of supramolecular compounds designed to selectively bind cationic residues such as lysine, to inhibit S. aureus biofilm formation by targeting PSMa1 aggregation.
Two molecular tweezers, CLR01 and CLR05, were evaluated for their effects on biofilm development. CLR01, featuring diphosphate groups, demonstrated strong inhibition of biofilm formation without significantly reducing bacterial viability at effective concentrations. In contrast, CLR05, with methylene-carboxylate units, exhibited even more potent anti-biofilm activity despite lower affinity for lysine residues. Both compounds disrupted the fibrillation of PSMa1 in vitro, as evidenced by thioflavin T fluorescence assays and transmission electron microscopy, which revealed shortened and fragmented fibrils. Notably, CLR01 induced complete suppression of ThT signal at equimolar ratios, while CLR05 showed dose-dependent inhibition, suggesting distinct mechanisms of action.
Structural analysis via nuclear magnetic resonance (NMR) spectroscopy confirmed that CLR01 binds directly to lysine side chains within the PSMa1 peptide, causing significant chemical shift perturbations and peak broadening indicative of tight inclusion complex formation. In contrast, CLR05 displayed weaker binding and no blue shift in fluorescence emission, implying interaction outside the tweezer cavity—likely through electrostatic or hydrophobic contacts with non-lysine regions. Molecular dynamics simulations further supported these findings, showing stable inclusion complexes with CLR01 but labile, non-inclusion interactions with CLR05, consistent with its enhanced disruption of preformed fibrils.
Importantly, the tweezers effectively inhibited biofilm formation in physiologically relevant environments, including 10% mouse serum and whole blood, as confirmed by scanning electron microscopy and crystal violet staining. These results indicate that the inhibitory effect is not compromised by biological matrices. Moreover, the compounds did not impair bacterial growth at sub-lethal concentrations, highlighting their antivirulence rather than bactericidal nature—a crucial advantage in minimizing selective pressure for resistance.Cerberus Antibody Purity & Documentation
Collectively, this work demonstrates that molecular tweezers represent a promising strategy for combating S.BDH2 Antibody In Vivo aureus biofilms by disrupting the self-assembly of PSMa1, a critical functional amyloid.PMID:35176431 The differential mechanisms of CLR01 and CLR05 suggest tunable design principles for next-generation anti-biofilm agents. Given the rising threat of antibiotic-resistant strains like MRSA, these findings open new avenues for therapeutic development focused on dismantling the structural foundation of bacterial persistence.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com