MT Research Project

This Thesis Research Project is directed by Prof.Silvia Atrian and Prof.Mercè Capdevila.

Jordi Domenech Research Project

Go to Jordi's Metallothionein Research Page.

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1.-A general study on the structure-function relationship in MTs

My research subject deals with the relationship between the primary structure of plant, Protozoa and Invertebrate Metallothioneins and several aspects of their molecular features, including peptide folding, metal-binding abilities, metal coordination preferences and structure, in order to get information about the chemical and geometric functional constraints defining the evolutionary paths of this family of proteins.

To this aim, we aborded the characterization of the metal-binding behaviour of several representative MTs, listed here bu the methodology described in "How we study MTs".

 

 

2-Nematoda Caenorhabditis elegans CeMT2.

3-Insecta Drosophila melanogaster MTNA, MTNB, MTNC, MTND.

4-Echinoderma Stryngulocentrotus purpuratus SpMTA.

5-Molluscan Mytilus edulis Me10MT-IV.

6-Crustacean Homarus americanus MTH.

7-Plant Quercus suber QsMT.

8-Protozoan Tetrahymena pyriformis TpMT1.

 

9-Sulphides in Metallothioneins

10-Dimers in Metallothioneins

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    MT Research Project

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Jordi Domenech Research Project

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  Nematoda Caenorhabditis elegans CeMT2.

 

There are few data on the literature about the folding of this MT or  its metal preferences.

The presence of a C-terminal Histidine is not habitual in MTs, and our first results show that this Histidine  residue could play a principal  role in Metal cordination.

This studies have been object of a communication, available at the Publications section.

The characterization of the Metal-binding habilities of CeMT2 is a collaboration between the UB and UAB Research groups, directed by Prof. Mercè Capdevila and Prof. Silvia Atrian.

 

   

 

MVCKCDCKNQNCSCNTGTKDCDCSDAKCCEQYCCPTASEKKCCKSGCAGGCKCANCECAQAAH

 

 

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    MT Research Project

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Jordi Domenech Research Project

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Drosophila melanogaster MTNA, MTNB, MTNC, MTND

 

MTNA and MTNB Drosophila MT forms show a preference for cooper, and Drosophila reveals to be the first metazoan which have not a Zn-preferent MT described. We are working in the characterization of two new Drosophila MT isoforms, MTNC and MTND.

The functional characterization  of Drosophila MT forms is being  performed in a collaboration between  the UAB Research Group  of Prof. Mercè Capdevila, the UB Research group of Prof. Silvia Atrian and the Research Group of Prof. Walter Schaffner, of Zurich University.

 

   

 

MTNA     MPCPCGSGCKCASQATKGSCNCGSDCKCGGDKKSACGCSE

 MTNB     MVCKGCGTNCQCSAQKCGDNCACNKDCQCVCKNGPKDQCCSNK

MTNC     MVCKGCGTNCKCQDTKCGDNCACNQDCKCVCKNGPKDQCCKSK

MTND     MGCKACGTNCQCSATKCGDNCACSQQCQCSCKNGPKDKCCSTKN

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Stryngulocentrotus purpuratus SpMTA

 

Echinoderma MT structure have been described by other groups, showing that, as primary sequence suggested, this MT is composed by the canonical two domains (alpha and beta) structure, but ordered in the opposite sense of mammalian MT.

 In spite of only little differences should be expectable, our results show some differences with the metal-binding behauviour of the canonical mammalian MTs, so suggesting that the participation of alpha and beta domains in the structure of the whole molecule is not additive.

Results are yet under evaluation. The characterization of the Metal-binding habilities of SpMTA  is being performed as a collaboration between  UAB Research Group  of Prof. Mercè Capdevila and the UB Research Group of Prof.Sílvia Atrian

 

   

 

MPDVKCVCCTEGKECACFGQDCCVTGECCKDGTCCGICTNAACKCANGCKCGSGCSCTEGNCAC

   

 

 

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Mytilus edulis Me10MT-IV.

Molluscan MTs are the invertebrate MTs with a higher sequence similarity to vertebrate MT's, but doesn't present the canonical alpha and beta domains.

This make of these MTs an important element of the study of the evolutionary paths of these proteins. Until this moment, most of data on molluscan MTs deals with the expression of these MTs rather than their metal-binding abilities.

We are at this moment studying the metal-binding behauviour of one of these MT forms, results are yet under evaluation.

The characterization of the metal-binding habilities of MeMT10-IV  is being performed as a collaboration between the UAB Research Group  of Prof. Mercè Capdevila and the UB Research Group of Prof.Silvia Atrian.

   

 

 

MPAPCNCIETNVCICDTGCSGEGCRCGDACKCSGADCKCSGCKVVCKCSGSCACEGGCTGPSTCKCAPGCSCK

 

 

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Jordi Domenech Research Project

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Homarus americanus MTH.

 

 

MTH have a structure composed of two domains beta, and the study of its metal binding ablities performed by the UB/UAB Research groups resulted in the proposition of a general classification of MTs regarding their Zn/Cu preferences.

 

New  data related to Cu-aggregates and the participation of other ions are under evaluation in the frame of the collaboration between these two Research Groups.

 

   

 

MPGPCCKDKCECAEGGCKTGCKCTSCRCAPCEKCTSGCKCPSKDECAKTCSKPCKCCP

 

 

 

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Jordi Domenech Research Project

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Quercus suber QsMT.

 

 

Nearly 200 plant MT's have been described, but few studies focuse on their metal-binding abilities, and there are very few experimental data useful to describe the folding model of these exceptional MTs.

 Most of the plant MTs show a  conserved "spacer" domain devoid of Cysteines, with an unknown function.

 As a result from the research  collaboration between the Cork Research group of Prof. Marissa Molinas from the University of Girona, the UB Research group of Prof.silvia Atrian and the UAB Research Group of Prof Mercè Capdevila, in a recent publication (available at the Publications section) we propose  a folding model for  QsMT, the first complete characterization of a plant MT with Zn, Cu and Cd.

 

   

 

 

MSCCGGNCGCGTGCKCGSGCGGCKMFPDISSEKTTTETLIVGVAPQKTHFEGSEMGVGAENGCKCGSNCTCDPCNCK

 

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Tetrahymena pyriformis TpMT1.

 

 

Tetrahymena genera have 5 MTs forms.4 out 5 of these  isoforms present a special sequence motif: Cys triplets.

This special sequence motif is only present in three other species: Eisenia foetida, Callinestes sapidus, Crassostea gigas, and could present special features on metal cordination.

Our studies have been object of a recent communication, available at the Publications section. The characterization of the Metal-binding habilities of TpMT1  is being performed as a collaboration between the UAB Research Group  of Prof. Mercè Capdevila and the UB Research Group of Prof.Silvia Atrian.

 

 

   

 

 

MDKVNNNCCCGENAKPCCTDPNSGCCCVSETNNCCKSDKKECCTGTGEGCKCTGCKCCQPAK-SGCCCGDKAKACCTDPNSGCCCSSKTNKCCDSTNKTECKTCECCK

 

 

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Jordi Domenech Research Project

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Sulphides in Metallothioneins.

In Phytochelatins, enzymatically synthesised-peptides with structural similarities with Metallothioneins, it has been demonstrated that sulphide ions takes an important part in their structure.

In Metallothioneins, in spite of the presence of Phospate or Chloride ions had been demonstrated in Metal-MT aggregates, no data on sulphide ions were available.

By GC-FPD analysis in combination with spectrometric and spectroscopic thechniques, our group demonstrated the presence of sulphide ions in in vivo-constituted Metal-MT aggregates of a broad range of phyla. More information disposable at the Publications section.

The implications of sulphide ions in MT functionality are being discussed.

   

 

 

 

 

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Dimers in Metallothioneins.

 

Polymerization and dimerization events have been observed in in-vitro experiments with Metallothioneins and observed by Mass Spectrometry by other groups.

Untill this moment, no similar aggregates were observed from in-vivo synthesised aggregates.

Recent studies in the characterization of in-vivo synthesised mutant forms of QsMT demonstrated the presence of dimeric forms of the metallopeptides by ESI-MS, so demonstrating the capability of this thechnique to detect in-vivo-constituted dimers of MT-like peptides.

These results are the result of the collaborations between the Cork Research Group of Prof.M.Molinas of Universitat de Girona and UAB-UB Research groups of Prof.S.Atrian and M.Capdevila, and have been object or a recent communication, available at the Publications section..

 

   

 

 

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