Does Variation of the Inter-Domain Linker Sequence Modulate the Metal Binding Behaviour of Helix pomatia Cd-Metallothionein?
Gil-Moreno, Selene (Universitat Autònoma de Barcelona. Departament de Química)
Jiménez Martí, Elena (Universitat de Barcelona. Departament de Genètica)
Palacios Bonilla, Òscar (Universitat Autònoma de Barcelona. Departament de Química)
Zerbe, Oliver (University of Zurich. Institute of Organic Chemistry)
Dallinger, Reinhard (University of Innsbruck. Institute of Zoology and Center of Molecular Biosciences)
Capdevila Vidal, Mercè (Universitat Autònoma de Barcelona. Departament de Química)
Atrian i Ventura, Sílvia (Universitat de Barcelona. Departament de Genètica)

Data:	2016
Resum:	Snail metallothioneins (MTs) constitute an ideal model to study structure/function relationships in these metal-binding polypeptides. Helix pomatia harbours three MT isoforms: the highly specific CdMT and CuMT, and an unspecific Cd/CuMT, which represent paralogous proteins with extremely different metal binding preferences while sharing high sequence similarity. Preceding work allowed assessing that, although, the Cys residues are responsible for metal ion coordination, metal specificity or preference is achieved by diversification of the amino acids interspersed between them. The metal-specific MT polypeptides fold into unique, energetically-optimized complexes of defined metal content, when binding their cognate metalions, while they produce a mixture of complexes, none of them representing a clear energy minimum, with non-cognate metal ions. Another critical, and so far mostly unexplored, region is the stretch linking the individual MT domains, each of which represents an independent metal cluster. In this work, we have designed and analyzed two HpCdMT constructs with substituted linker segments, and determined their coordination behavior when exposed to both cognate and non-cognate metal ions. Results unequivocally show that neither length nor composition of the inter-domain linker alter the features of the Zn(II)- and Cd(II)-complexes, but surprisingly that they influence their ability to bind Cu(I), the non-cognate metal ion.
Ajuts:	Ministerio de Economía y Competitividad BIO2012-39682-C02-01 Ministerio de Economía y Competitividad BIO2012-39682-C02-02 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-423
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Cd-isoform ; Domain linker sequence ; Helix pomatia ; Metallothionein ; Metal binding
Publicat a:	International journal of molecular sciences, Vol. 17 Núm. 6 (2016) , p. 1-13, ISSN 1422-0067

DOI: 10.3390/ijms17010006
PMID: 26703589

13 p, 1.3 MB

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