Lead: Its Effects on Environment and Health
Ed. by Sigel, Astrid / Sigel, Helmut / Sigel, Roland K.O.
With contrib. by Aoki, Katsuyuki / Aschner, Michael / Cullen, Jay T. / Farkas, Etelka / Filella, Montserrat / Hauser, Peter / Klotz, Katrin / Küpper, Hendrik / Maret, Wolfgang / Stewart, Theodora J. / Stillman, Martin J. / Pecoraro, Vincent L. / Pohl, Hana R. / Tylkowski, Bartosz
Series:Metal Ions in Life Sciences 17
- eBook (PDF)
- Publication Date:
- April 2017
- Copyright year:
9. Lead(II) Binding in Metallothioneins
Wong, Daisy L. / Merrifield-MacRae, Maureen E. / Stillman, Martin J.
Heavy metal exposure has long been associated with metallothionein (MT) regulation and its functions. MT is a ubiquitous, cysteine-rich protein that is involved in homeostatic metal response for the essential metals zinc and copper, as well as detoxification of heavy metals; the most commonly proposed being cadmium. MT binds in vivo to a number of metals in addition to zinc, cadmium and copper, such as bismuth. In vitro, metallation with a wide range of metals (especially mercury, arsenic, and lead) has been reported using a variety of analytical methods. To fully understand MT and its role with lead metabolism, we will describe how MT interacts with a wide variety of metals that bind in vitro. In general, affinity to the metal-binding cysteine residues of MT follows that of metal binding to thiols: Zn(II) < Pb(II) < Cd (II) < Cu(I) < Ag(I) < Hg(II) < Bi(III). To introduce the metal binding properties that we feel directly relate to the metallation of metallothionein by Pb(II), we will explore MT’s interactions with metals long known as toxic, particularly, Cd(II), Hg(II), and As(III), along with xenobiotic metals, and how these metal-binding studies complement those of lead binding. Lead’s effects on an organism’s physiological functions are not fully understood, but it is known that chronic exposure inflicts amongst other factors pernicious anemia and developmental issues in the brain, especially in children who are more vulnerable to its toxic effects. Understanding the interaction of lead with metallothioneins throughout the biosphere, from bacteria, to algae, to fish, to humans, is important in determining pathways for lead to enter and damage physiologically significant protein function, and thereby its toxicity.
Daisy L. Wong, Maureen E. Merrifield-MacRae, Martin J. Stillman (2017). 9. Lead(II) Binding in Metallothioneins. In Astrid Sigel, Helmut Sigel, Roland K.O. Sigel (Eds.), Lead – Its Effects on Environment and Health (pp. 241–270). Berlin, Boston: De Gruyter. https://doi.org/10.1515/9783110434330-009
Book DOI: https://doi.org/10.1515/9783110434330
Online ISBN: 9783110434330© 2017 Walter de Gruyter GmbH, Berlin/Munich/Boston