Complete amino acid sequences of five dimeric and four monomeric forms of metallothionein from the edible mussel Mytilus edulis

Eur J Biochem. 1993 Nov 15;218(1):183-94. doi: 10.1111/j.1432-1033.1993.tb18364.x.


Cadmium-induced metallothioneins from the common sea mussel, Mytilus edulis, were shown to comprise of two groups of isoforms having apparent molecular masses of 10 kDa and 20 kDa. The 10-kDa group was resolved by anion-exchange chromatography into four fractions while the 20-kDa group was resolved into three fractions using this method. After metal removal and S-methylation of the cysteine residues using methyl-p-nitrobenzenesulphonate the complete amino acid sequences were determined. Five isoforms of the 20-kDa group were shown to possess monomeric units consisting of 71 amino acids. These proteins were distinct from the four 72-amino-acid proteins of the 10-kDa group. The FASTA algorithm has been used to compare the degree of similarity between the mussel metallothionein MT-10-IV isoform and other metallothioneins. The mussel MT-10-IV isoform exhibited substantial similarity to other molluscan metallothioneins. Moreover, the mussel metallothionein exhibited more similarity to vertebrate metallothioneins than to those of non-molluscan invertebrates, thus suggesting that the mussel metallothioneins are class I metallothioneins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bivalvia / chemistry*
  • Chromatography, Gel
  • Chromatography, High Pressure Liquid
  • Chromatography, Ion Exchange
  • Humans
  • Metallothionein / chemistry*
  • Metallothionein / isolation & purification
  • Molecular Sequence Data
  • Peptide Mapping
  • Sequence Homology, Amino Acid


  • Metallothionein

Associated data

  • GENBANK/P80246
  • GENBANK/P80247
  • GENBANK/P80248
  • GENBANK/P80249
  • GENBANK/P80251
  • GENBANK/P80252
  • GENBANK/P80253
  • GENBANK/P80257
  • GENBANK/P80258