title: Binding of an oxindole alkaloid from Uncaria tomentosa to amyloid protein (Abeta1-40).
abstract: The primary aim of this work was to determine the interactions of an oxindole alkaloid (mitraphylline) isolated from Uncaria tomentosa with beta-amyloid 1-40 (Abeta1-40 protein) applying the capillary electrophoresis (CE) method. Specifically the Hummel-Dreyer method and Scatchard analysis were performed to study the binding of oxindole alkaloids with Abeta1-40 protein. Prior to these studies extraction of the alkaloid of interest was carried out. Identification of the isolated alkaloid was performed by the use of thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) combined with electrospray ionization mass spectrometry (ESI-MS). The proposed approach was proved to be an efficient and accurate method for specific compound isolation and identification purposes. Moreover, analytical information from the CE approach can be considered as the valuable tool for binding constant determination. The binding constant of mitraphylline with Abeta1-40 protein determined by the Hummel-Dreyer method and Scatchard analysis equals K = 9.95 x 10(5) M(-1). The results obtained showed the significant binding of the tested compound with Abeta1-40 protein. These results are discussed and interpreted in the view of developing a strategy for identification of novel compounds of great importance in Alzheimer disease therapy.
authors.affiliation: Department of Biopharmaceutics and Pharmacodynamics, Medical University of Gdańsk, Gen. J. Hallera 107, 80-416 Gdańsk, Poland. teresafr@amg.gda.pl
authors.forename: Teresa
authors.initials: T
authors.lastname: Frackowiak
authors.forename: Tomasz
authors.initials: T
authors.lastname: Baczek
authors.forename: Kaliszana
authors.initials: K
authors.lastname: Roman
authors.forename: Beata
authors.initials: B
authors.lastname: Zbikowska
authors.forename: Michał
authors.initials: M
authors.lastname: Gleńsk
authors.forename: Izabela
authors.initials: I
authors.lastname: Fecka
authors.forename: Wojciech
authors.initials: W
authors.lastname: Cisowski
mesh_terms: D000470:Alkaloids / Q000302:isolation & purification / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000302:isolation & purification / Q000378:metabolism*; D001665:Binding Sites; D020948:Cat's Claw / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D019075:Electrophoresis, Capillary; D007211:Indoles / Q000302:isolation & purification / Q000378:metabolism*; D013058:Mass Spectrometry; D000078183:Oxindoles; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D000470:Alkaloids; D016229:Amyloid beta-Peptides; D007211:Indoles; D000078183:Oxindoles; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C022960:2-oxindole