title: Fatty acid binding sites of human and bovine albumins: differences observed by spin probe ESR.
abstract: Bovine and human serum albumins and recombinant human albumin, all non-covalently complexed with 5- and 16-doxyl stearic acids, were investigated by ESR spectroscopy in solution over a range of pH values (5.5-8.0) and temperatures (25-50 degrees C), with respect to the allocation and mobility of fatty acid (FA) molecules bound to the proteins and conformation of the binding sites. In all proteins bound FA undergo a permanent intra-albumin migration between the binding sites and inter-domain residence. Nature identity of the recombinant human albumin to its serum-derived analog was observed. However, the binding sites of bovine albumin appeared shorter in length and wider in diameter than those of human albumin. Presumably, less tightly folded domains in bovine albumin allow better penetration of water molecules in the interior of the globule that resulted in higher activation energy of FA dissociation from the binding site. Thus, the sensitive technique based on ESR non-covalent spin labeling allowed quantitative analysis and reliable comparison of the fine features of binding proteins.
authors.affiliation: Department of Research and Development, MedInnovation GmbH, D-13599 Berlin, Germany. v.muravsky@gmail.com
authors.forename: Vladimir
authors.initials: V
authors.lastname: Muravsky
authors.forename: Tatjana
authors.initials: T
authors.lastname: Gurachevskaya
authors.forename: Stephen
authors.initials: S
authors.lastname: Berezenko
authors.forename: Kerstin
authors.initials: K
authors.lastname: Schnurr
authors.forename: Andrey
authors.initials: A
authors.lastname: Gurachevsky
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005227:Fatty Acids / Q000378:metabolism*; D006801:Humans; D008962:Models, Theoretical; D011487:Protein Conformation; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry* / Q000378:metabolism; D013113:Spin Labels; D013696:Temperature; D013816:Thermodynamics
chemical_list: D005227:Fatty Acids; D012709:Serum Albumin; D013113:Spin Labels; D012710:Serum Albumin, Bovine