22CD

Crystal structure of HSA in complex with ThiQu

This is a non-PDB format compatible entry.

Summary for 22CD

• Entry DOI: 10.2210/pdb22cd/pdb
• Descriptor: Albumin, 2-[methyl-[6-[5-[(~{E})-2-(1-methylquinolin-1-ium-4-yl)ethenyl]thiophen-2-yl]naphthalen-2-yl]amino]ethanol (2 entities in total)
• Functional Keywords: albumin, photosensitizer, transport protein
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 2
• Total formula weight: 134045.64

Authors

Chen, X.,Shi, M.W.,Fang, B.,Li, L. (deposition date: 2026-01-06, release date: 2026-10-28)

Primary citation

Fang, B.,Wang, W.,Bai, H.,Li, P.,Si, M.,Peng, B.,Chen, X.,Yang, X.,Li, L.
Albumin Orchestrates Type-I ROS Conversion for Efficient Intracellular Bacterial Clearance.
Adv Mater, :e75340-e75340, 2026

PubMed Abstract: Type-I photosensitization addresses the dilemma of intracellular bacterial hypoxia-induced photodynamic therapeutic (PDT) inefficacy, yet precise targeting and eradicating sequestered pathogens remains a formidable challenge. Herein, we engineer an albumin-based photodynamic conversion nanoparticles integrating target-specific recognition with controlled antibacterial functions to precisely eliminate intracellular pathogens and restore infected cell activity. Mechanistic studies reveal a vertically-crossed conformation that promotes intramolecular electron transfer and charge separation, redirecting photosensitizer (PS) reactivity toward type-I reactive oxygen species (ROS) generation. Electron-rich albumin further enhances cationic PS recycling, photostability, and O production, while its selective cytoplasmic delivery via receptor/charge interactions enables preferential accumulation in intracellular bacteria, with reduced off-target organelle engagement. We demonstrate application in S. aureus-infected sepsis showing high type-I ROS levels for antibacterial function from the nanoparticles to restore redox and immune homeostasis without noticeable toxicity. This work pioneers a conformationally-gated ROS conversion approach for eliminating intracellular bacterial infections, merging mechanistic precision with therapeutic potential for clinical sepsis management.

PubMed: 42860758
DOI: 10.1002/adma.75340

Experimental method

X-RAY DIFFRACTION (3.25 Å)