Accumulation and interaction of hypericin in low-density lipoprotein--a photophysical study.
The accumulation and interaction of hypericin with the biologically important macromolecule, low-density lipoprotein (LDL), is investigated using various steady-state and time-resolved fluorescence measurements. It is concluded that multiple hypericins can penetrate considerably deeply into the LDL molecule. Up to approximately 20 nonaggregated hypericin molecules can enter LDL; but upon increasing the hypericin concentration, the fluorescence lifetime of hypericin decreases drastically, suggesting most likely the self-quenching of aggregated hypericin. There is also evidence of energy transfer from tryptophans of the constituent protein, apoB-100, to hypericin in LDL. The results demonstrate the ability of LDL to solubilize hypericin (a known photosensitizer) in nonaggregated form, which has implications for the construction of drug delivery systems.
Mukherjee
Prasun
P
Department of Chemistry, Iowa State University, Ames, IA, USA.
Adhikary
Ramkrishna
R
Halder
Mintu
M
Petrich
Jacob W
JW
Miskovsky
Pavol
P
D000873:Anthracenes; D005453:Fluorescence; D008077:Lipoproteins, LDL / Q000737:chemistry*; D015394:Molecular Structure; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D017319:Photosensitizing Agents / Q000737:chemistry*; D012995:Solubility; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014364:Tryptophan / Q000737:chemistry
D000873:Anthracenes; D008077:Lipoproteins, LDL; D017319:Photosensitizing Agents; D010569:Perylene; C004965:hypericin; D014364:Tryptophan