title: Kinetics of incorporation/redistribution of photosensitizer hypericin to/from high-density lipoproteins.
abstract: By means of fluorescence spectroscopy we have studied the kinetics of interaction of a photosensitizer hypericin (Hyp) with high-density lipoproteins (HDL). Hyp is incorporated into HDL molecules as monomer till ratio Hyp/HDL ∼8:1 and above this ratio forms non-fluorescent aggregates. This number is different from that found in the case of Hyp incorporation into low-density lipoprotein (LDL) molecules (8:1 vs 30:1). The difference is mainly attributed to the smaller size of HDL in comparison with LDL molecule. Biphasic kinetics of Hyp association with HDL was observed. The rapid phase of incorporation is completed within seconds, while the slow one lasts several minutes. The kinetics of the association of Hyp molecules with free HDL, Hyp/HDL=10:1 complex and the redistribution of Hyp from Hyp/HDL=70:1 complex to free HDL molecules reveal a qualitative similar characteristics of these processes with those observed for the interaction of Hyp with LDL. However, the incorporation of Hyp into HDL in the "slow" phase is more rapid than to LDL and extend of Hyp penetration into lipoproteins in the fast phase is also much higher in the case of HDL. The lower concentration of cholesterol molecules in outer shell of HDL particles is probably the determining factor for the more rapid kinetics of Hyp incorporation to and redistribution from these molecules when comparing with LDL particles.
authors.affiliation: Department of Biophysics, Faculty of Science, Safarik University, Kosice, Slovakia.
authors.forename: Jaroslava
authors.initials: J
authors.lastname: Joniova
authors.affiliation: Department of Biophysics, Faculty of Science, Safarik University, Kosice, Slovakia; Department of Physics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic.
authors.forename: Luboslava
authors.initials: L
authors.lastname: Buriankova
authors.affiliation: Department of Biophysics, Faculty of Science, Safarik University, Kosice, Slovakia; Department of Adaptation Biotechnologies, Czech Globe, Drasov, Czech Republic.
authors.forename: Diana
authors.initials: D
authors.lastname: Buzova
authors.affiliation: Department of Biophysics, Faculty of Science, Safarik University, Kosice, Slovakia; Center for Interdisciplinary Biosciences, Faculty of Science, Safarik University, Kosice, Slovakia.
authors.forename: Pavol
authors.initials: P
authors.lastname: Miskovsky
authors.affiliation: Department of Biophysics, Faculty of Science, Safarik University, Kosice, Slovakia; Center for Interdisciplinary Biosciences, Faculty of Science, Safarik University, Kosice, Slovakia. Electronic address: daniel.jancura@upjs.sk.
authors.forename: Daniel
authors.initials: D
authors.lastname: Jancura
mesh_terms: D000873:Anthracenes; D002460:Cell Line; D002626:Chemistry, Pharmaceutical; D065546:Drug Liberation; D008075:Lipoproteins, HDL / Q000737:chemistry*; D008077:Lipoproteins, LDL / Q000737:chemistry; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D017319:Photosensitizing Agents / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D000873:Anthracenes; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D017319:Photosensitizing Agents; D010569:Perylene; C004965:hypericin
keywords: Aggregation; Drug delivery; Fluorescence; High- and low- density lipoproteins; Hypericin