Binding of transition metal ions to albumin: Sites, affinities and rates

• Published in: Biochimica et biophysica acta Vol. 1830; no. 12; pp. 5444 - 5455
• Main Authors: Bal, Wojciech, Sokołowska, Magdalena, Kurowska, Ewa, Faller, Peter
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2013; Elsevier
• Subjects: Albumin; Binding constants; binding properties; binding proteins; Binding Sites; blood; blood flow; cadmium; cerebrospinal fluid; Chemical Sciences; cobalt; Coordination chemistry; copper; dissociation; drugs; gold; human serum albumin; humans; Kinetics; Metal ions; metals; Metals - chemistry; Metals - metabolism; Models, Molecular; Molecular Structure; nickel; physiological transport; Protein Binding; Serum Albumin - chemistry; Serum Albumin - metabolism; toxicity; zinc; Albumin; Binding constants; Metal ions
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2013.06.018

Serum albumin is the most abundant protein in the blood and cerebrospinal fluid and plays a fundamental role in the distribution of essential transition metal ions in the human body. Human serum albumin (HSA) is an important physiological transporter of the essential metal ions Cu2+, and Zn2+ in the bloodstream. Its binding of metals like Ni2+, Co2+, or Cd2+ can occur in vivo, but is only of toxicological relevance. Moreover, HSA is one of the main targets and hence most studied binding protein for metallodrugs based on complexes with Au, Pt and V. We discuss i) the four metal-binding sites so far described on HSA, their localization and metal preference, ii) the binding of the metal ions mentioned above, i.e. their stability constants and association/dissociation rates, their coordination chemistry and their selectivity versus the four binding sites iii) the methodology applied to study issues of items i and ii and iv) oligopeptide models of the N-terminal binding site. Albumin has four partially selective metal binding sites with well-defined metal preferences. It is an important regulator of the blood transport of physiological Cu(II) and Zn(II) and toxic Ni(II) and Cd(II). It is also an important target for metal-based drugs containing Pt(II), V(IV)O, and Au(I). The thorough understanding of metal binding properties of serum albumin, including the competition of various metal ions for specific binding sites is important for biomedical issues, such as new disease markers and design of metal-based drugs. This article is part of a Special Issue entitled Serum Albumin. •Human Serum Albumin (HSA) is a versatile carrier of metal ions.•HSA contains four specific metal binding sites.•HSA binds and transports physiological, toxic and medicinal metals.•HSA may be a regulatory protein via crosstalk of metal and ligand binding.