Phosphatidylserine Reversibly Binds Cu2+ with Extremely High Affinity
| Autor: | Matthew F. Poyton, Aaron D. Robison, Paul S. Cremer, Xiao Cong, Christopher F. Monson, Chunming Liu, Hudson Pace |
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| Rok vydání: | 2012 |
| Předmět: |
Chromatography
Quenching (fluorescence) Cations Divalent Lipid Bilayers Complex formation Kinetics Phosphatidylserines General Chemistry Phosphatidylserine Hydrogen-Ion Concentration Microfluidic Analytical Techniques Photochemistry Biochemistry Article Catalysis Dissociation (chemistry) Orders of magnitude (mass) Dissociation constant chemistry.chemical_compound Colloid and Surface Chemistry chemistry Lipid bilayer Copper |
| Zdroj: | Journal of the American Chemical Society. 134:7773-7779 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja212138e |
| Popis: | Phosphatidylserine (PS) embedded within supported lipid bilayers (SLBs) was found to bind Cu2+ from solution with extraordinarily high affinity. In fact, the equilibrium dissociation constant was in the femtomolar range. The resulting complex formed in a 1:2 Cu2+ to PS ratio and quenches a broad spectrum of lipid-bound fluorophores in a reversible and pH-dependent fashion. At acidic pH values, the fluorophores were almost completely unquenched, while at basic pH values significant quenching (85–90%) was observed. The pH at which the transition occurred was dependent on the PS concentration and ranged from approximately pH 5 to 8. The quenching kinetics was slow at low Cu2+ concentrations and basic values pH (up to several hours), while the unquenching reaction was orders of magnitude more rapid upon lowering the pH. This was consistent with diffusion limited complex formation at basic pH, but rapid dissociation under acidic conditions. The tight binding of Cu2+ to PS may have physiological consequences under certain circumstances. |
| Databáze: | OpenAIRE |
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