The zn- or cu-thionein character of a metallothionein determines its metal load when synthesized in physiological (metal-unsupplemented) conditions.
The present work comprises the recombinant synthesis of four metallothioneins (MTs) in metal-unsupplemented cultures and the characterization of the recovered metal complexes by means of analytical and spectrometric techniques. The four MTs are two Drosophila (MtnA and MtnB), one yeast (Crs5), and one mouse (mMT1) metallothionein isoforms. These four MTs exhibit distinct metal binding preferences, from a clear Cu-thionein character to a definite Zn-thionein nature, respectively. Although in all cases, the only metal ion present in the purified complexes is Zn(2+), our results highlight an inherently different behaviour of those two types of MTs, in conditions that would mimic their synthesis in physiological environments. Therefore, intrinsically different roles can be hypothesized for the constitutively-produced MT peptides in the absence of any metal overload, depending on their Zn- or Cu-thionein character.
Capdevila
Mercè
M
Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain. merce.capdevila@uab.cat
Palacios
Oscar
O
Atrian
Sílvia
S
Anal Chem. 1988 Dec 15;60(24):2683-6
3245594
FEBS Lett. 2003 Jan 2;533(1-3):72-8
12505162
J Biol Chem. 2001 Aug 31;276(35):32835-43
11413132
Proc Natl Acad Sci U S A. 2001 May 8;98(10):5556-9
11331777
Mol Microbiol. 2007 Jan;63(1):256-69
17163970
Biochem J. 2007 Mar 15;402(3):551-8
17134375
Cell Mol Life Sci. 1997 Aug;53(8):681-8
9351472
Angew Chem Int Ed Engl. 2005 Jul 18;44(29):4618-22
15991200
J Inorg Biochem. 1997 Nov 15;68(3):157-66
9352652
FEBS Lett. 2000 Feb 11;467(2-3):189-94
10675536
Metallomics. 2009;1(3):229-34
21305119
Science. 2003 May 9;300(5621):931-6
12738850
Mutat Res. 2003 Dec 10;533(1-2):211-26
14643422
Proc Natl Acad Sci U S A. 1998 Jul 21;95(15):8428-30
9671693