Dimeric β-cyclodextrin-based supramolecular ligands and their copper(II) complexes as metalloenzyme models
| Autor: | Si Myung Byun, Bae Kwang-Hee, Won Bae Jeon |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Magnetic Resonance Spectroscopy
Stereochemistry Molecular Sequence Data Supramolecular chemistry In Vitro Techniques Ligands Biochemistry Inorganic Chemistry chemistry.chemical_compound Hydrolysis Deprotonation Amide Metalloproteins Pyridine Polymer chemistry Bifunctional Chelating Agents chemistry.chemical_classification Cyclodextrins Cyclodextrin beta-Cyclodextrins Esterases Nuclear magnetic resonance spectroscopy Hydrogen-Ion Concentration Enzymes Kinetics Carbohydrate Sequence Models Chemical chemistry Spectrophotometry Spectrometry Mass Matrix-Assisted Laser Desorption-Ionization Copper |
| Zdroj: | Journal of Inorganic Biochemistry. 71:163-169 |
| ISSN: | 0162-0134 |
| DOI: | 10.1016/s0162-0134(98)10049-1 |
| Popis: | New supramolecular ligands possessing linear 13- and 15-membered pyridine diamidetriamine chelators between the primary sides of two beta-cyclodextrin cavities were synthesized, and characterized by MALDI-MS, NMR, IR and UV-Visible spectroscopy. Fluorescence and pH-metric titration were carried out in order to ascertain their behavior as bifunctional hosts for fluorescent guests and Cu(II) ion. The pKa value for the Cu(II) promoted deprotonation of amide ligands was determined to be 6.2 from pH-absorbance profile. Above pH 8.0, two deprotonated amides and three amino groups chelated Cu(II) ion, and yielded penta-coordinated Cu(II) complexes. The Cu(II) complexes catalyzed the hydrolysis of p-nitrophenyl acetate, adamantate and amino acids. Especially, the complex containing 13-membered chelator is an artificial metalloesterase with catalytic rate constant kcat = 3.8 x 10(-3) min-1 and Michaelis constant K(m) = 3.5 x 10(-4) M for the hydrolysis of p-nitrophenyl adamantate via metal-hydroxide mechanism. |
| Databáze: | OpenAIRE |
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