title: Spectrofluorometric study of iron removal from bovine lactoferrin by ethylenediamminetetraacetic acid.
abstract: The kinetics of iron removal from the two metal binding sites of the bovine lactoferrin by ethylenediaminetetraacetic acid (EDTA) was investigated at pH 7.5 and 33°C. Solutions were buffered at pH 7.5 by 0.15 M Tris-HCl. Pseudo first-order rate constants as a function of ligand concentration were measured for iron removal from diferric lactoferrin and from N- and C-terminal monoferric lactoferrin. Diferric lactoferrin showed simple saturation behavior while both the monoferric forms showed a two-term dependence of kobs on ligand concentration that signifies two pathways for iron removal under the conditions applied. Moreover, the results show that the N-terminal site is more labile towards iron removal by EDTA than the C-terminal site.
authors.affiliation: Department of Chemistry, University of Karachi, Karachi 74900, Pakistan. shaznad7@yahoo.com
authors.forename: Shazia
authors.initials: S
authors.lastname: Nisar
authors.forename: S Arif
authors.initials: SA
authors.lastname: Kazmi
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D004492:Edetic Acid / Q000494:pharmacology*; D007501:Iron / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics*; D007502:Iron Chelating Agents / Q000494:pharmacology*; D007781:Lactoferrin / Q000737:chemistry / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism*; D008954:Models, Biological; D008956:Models, Chemical; D017434:Protein Structure, Tertiary / Q000187:drug effects; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D007502:Iron Chelating Agents; D004492:Edetic Acid; D007501:Iron; D007781:Lactoferrin