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Construction of α–α domains structure in recombinant monkey metallothionein-1
- Source :
- Journal of Inorganic Biochemistry. 92:183-192
- Publication Year :
- 2002
- Publisher :
- Elsevier BV, 2002.
-
Abstract
- The differences in metal-thiolate coordination and reactivity of mammalian metallothionein (MT) domains are closely related to their distinct, highly conservative cysteine number and position. Monkey metallothionein-1, containing a beta-domain with Cd(3)S(9) cluster and an alpha-domain with Cd(4)S(11) cluster, was used to evaluate the role of cysteine residues in the formation of MT's metal-thiolate clusters. The possible influence of cysteine residues on the binding and stability of MT domains has been examined with the metallothionein mutants: N4C, T27C and N4C/T27C, which possess ten or eleven cysteine residues in the re-constructed beta-domain, respectively. Assisted by study of UV, CD and electrospray ionization mass spectroscopy (ESI-MS) and their reactivity with DTNB (5,5'-dithiobis (2-nitrobenzoic acid)), we found that besides the original alpha-domain, some kinds of new domain containing 4-cadmium-thiolate clusters were formed in the N4C and N4C/T27C mutants of mkMT1. These new domains displayed metal binding and kinetic reactivity with DTNB similar to the alpha-domain. However, the thermal stability of the mutants was less stable than that of WT mkMT1. This might result from the disturbance of the inter-domains hydrogen bonds and of the non-cysteine amino acid residue arrangement.
Details
- ISSN :
- 01620134
- Volume :
- 92
- Database :
- OpenAIRE
- Journal :
- Journal of Inorganic Biochemistry
- Accession number :
- edsair.doi...........21e626ae11d0f1f613a351e7cfd43d75