Cysteine

Recent Findings on Cysteine

• Chiral copper–cysteine nanoparticles and wound-healing materials. A study synthesized two chiral copper–cysteine nanoparticle formulations, Cu-L-Cys and Cu-D-Cys, and systematically evaluated their chirality-dependent biological functions. The work was designed to address antibacterial and wound-healing challenges by incorporating the nanoparticles into functional silk sutures, linking cysteine-based coordination chemistry with antibacterial biomaterials and tissue repair 42592816Aug.

• ATG4B inhibition in esophageal squamous cell carcinoma. ATG4B was investigated as a therapeutic target because it is a cysteine protease and a key executor of autophagy. The study used structure-based discovery to identify a novel small-molecule ATG4B inhibitor and examined its capacity to modulate autophagy in esophageal squamous cell carcinoma therapy. This places cysteine-dependent proteolysis at the intersection of autophagy, tumor biology, Cancer treatment, and cellular proliferation 42385395Jul.

• Proteome-wide cysteine engagement by reactive metallo-scaffolds. Reactive metallo-scaffolds were developed as a platform for metallodrug discovery and proteome-wide target identification. The compounds combined a metal center and ligand architecture with an electrophilic chloroacetamide warhead, allowing covalent labeling through engagement of cysteine residues. The study illustrates how cysteine reactivity can be exploited to identify protein targets and characterize the engagement of reactive metal complexes 42430191Jul.

• Detection of enterovirus G and recombinant strains. A single-tube RT-ERA-CRISPR/Cas12a assay was developed and evaluated for simultaneous detection of enterovirus G and recombinant strains containing a papain-like cysteine protease gene insertion. In this context, cysteine protease is relevant as a genetically encoded viral feature used in assay design and strain detection, while CRISPR-Cas12a provides the nucleic-acid detection platform 42720869Sep.

• Covalent inhibitors of chikungunya virus nsP2 cysteine protease. Researchers used direct-to-biology synthesis and screening to develop covalent inhibitors of the chikungunya virus nsP2 cysteine protease. The enzyme was targeted because its protease activity is required for processing viral polyproteins and contributes to counteraction of host antiviral defenses, making it a proposed therapeutic intervention point for chikungunya virus infection 42720489Sep.

• Computational targeting of cruzain in Chagas disease. A computer-aided drug-design workflow investigated pyrazolone derivatives with reported antitrypanosomal activity and their putative interaction with cruzain, a cysteine protease essential for parasite survival. The approach combined quantitative structure–activity relationship analysis, molecular docking, molecular dynamics, and free-energy calculations to examine potential compound–protease interactions. The work connects cysteine-protease inhibition with antiparasitic drug discovery for Chagas disease 42714666Sep.

• Cysteine as a prognostic biomarker in intracerebral hemorrhage. A retrospective study examined plasma cysteine together with homocysteine and methionine in patients with intracerebral hemorrhage. It assessed the association of these metabolites with 90-day prognosis and evaluated their potential predictive value. The study therefore treated cysteine primarily as a circulating biochemical marker rather than as a drug target 42626963Aug.

• Covalent modification of SARS-CoV-2 main protease. Biochemical and cell-based assays, structural analysis, and resistance-mutant testing were used to investigate the heat shock protein inhibitor tanespimycin (17AAG). The study reported that 17AAG covalently binds the active-site cysteine of SARS-CoV-2 main protease, disrupts the protease’s secondary structure, and protects cells from main-protease-induced toxicity more effectively than nirmatrelvir in the reported experimental comparisons 42599674Aug.

• Cysteine-containing fibrinogen-γ-chain hydrogels. Recombinant fibrinogen-γ-chain was evaluated as a crosslinker for thiol–ene hydrogels. The presence of cysteine residues in the protein sequence makes it a source of thiol groups for thiol–ene reactions, supporting its use as a thiol donor in biomaterial fabrication 41933468Apr.

Together, these publications extend the broad cysteine-related biomedical research theme rather than forming a single mechanistic research program. Across the set, cysteine is used in distinct ways: as a reactive residue for covalent inhibitor design, as the catalytic basis of protease activity, as a component of copper-containing nanoparticles, as a circulating metabolite associated with prognosis, and as a chemical handle for hydrogel formation. The studies also intersect with glutathione and reactive oxygen species biology, cytotoxicity and cell death in cancer research, pathogen detection, and therapeutic screening.