Molecular cloning of α-2-macroglobulin from hemocytes of common periwinkle Littorina littorea

Fish Shellfish Immunol. 2014 Aug;39(2):136-7. doi: 10.1016/j.fsi.2014.05.007. Epub 2014 May 14.


We report the sequence of the proteinase inhibitor with a wide inhibition spectrum, α-2-macroglobulin (α2M), belonging to the thioester superfamily of proteins. This is the first α2M sequence from coenogastropod prosobranch snails. The full-length cDNA was cloned by RACE method, spans 7897 bp and contains an open reading frame of 5460 bp. The ORF encodes a protein of 1819 amino acids. The deduced mature protein contains 1795 amino acids with a molecular weight of 200 kDa and isoelectric point of 5.00. Littorina littorea α2M bears 4 conserved α2M domains and one internal thioester. Phylogenetic analysis showed that the sequence forms well supported cluster with Mollusca species and other representatives of Lophotrochozoa.

Keywords: Coenogastropoda; Hemocytes; Innate immunity; Mollusca; Proteinase inhibitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cloning, Molecular
  • Cluster Analysis
  • DNA Primers / genetics
  • DNA, Complementary / genetics
  • Hemocytes / metabolism*
  • Immunity, Innate / genetics*
  • Models, Genetic
  • Molecular Sequence Data
  • Open Reading Frames / genetics
  • Phylogeny*
  • Sequence Analysis, DNA
  • Snails / genetics*
  • Snails / immunology
  • alpha-Macroglobulins / genetics*
  • alpha-Macroglobulins / metabolism


  • DNA Primers
  • DNA, Complementary
  • alpha-Macroglobulins