title: Greatly enhanced binding of a cationic porphyrin towards bovine serum albumin by cucurbit[8]uril.
abstract: Binding affinity towards serum albumin and intracellular proteins is of importance for a photodynamic therapy (PDT) sensitizer to selectively localize in tumours and efficiently induce cell death. In this paper, it was found that cucurbit[8]uril (CB8) can greatly improve the binding affinity of 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin tetra(p-toluenesulfonate) (TMPyP), a promising PDT photosensitizer, towards bovine serum albumin (BSA). Absorption, fluorescence emission, (1)H NMR, dynamic light scattering, atomic force microscope, as well as protein photocleavage measurements suggest that the binding enhancement originates from the formation of a ternary complex of CB8·TMPyP·tryptophan residues. This finding opens up a new approach for the development of more efficient PDT agents.
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
authors.forename: Wanhua
authors.initials: W
authors.lastname: Lei
authors.forename: Guoyu
authors.initials: G
authors.lastname: Jiang
authors.forename: Qianxiong
authors.initials: Q
authors.lastname: Zhou
authors.forename: Baowen
authors.initials: B
authors.lastname: Zhang
authors.forename: Xuesong
authors.initials: X
authors.lastname: Wang
mesh_terms: D000818:Animals; D002412:Cations / Q000737:chemistry; D002417:Cattle; D047028:Macrocyclic Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D018625:Microscopy, Atomic Force; D017319:Photosensitizing Agents / Q000737:chemistry; D011166:Porphyrins / Q000737:chemistry*; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D000099246:Cucurbit(n)urils
chemical_list: D002412:Cations; D047028:Macrocyclic Compounds; D017319:Photosensitizing Agents; D011166:Porphyrins; D012710:Serum Albumin, Bovine; D000099246:Cucurbit(n)urils; C021096:tetra(4-N-methylpyridyl)porphine