Diverse immune functions of hemocyanins

Dev Comp Immunol. 2014 Jul;45(1):43-55. doi: 10.1016/j.dci.2014.01.021. Epub 2014 Jan 31.


Substantial evidence gathered recently has revealed the multiple functionalities of hemocyanin. Contrary to previous claims that this ancient protein is involved solely in oxygen transport within the hemolymph of invertebrates, hemocyanin and hemocyanin-derived peptides have been linked to key aspects of innate immunity, in particular, antiviral and phenoloxidase-like activities. Both phenoloxidase and hemocyanin belong to the family of type-3 copper proteins and share a high degree of sequence homology. While the importance of phenoloxidase in immunity and development is well characterised, the contribution of hemocyanin to biological defence systems within invertebrates is not recognised widely. This review focusses on the conversion of hemocyanin into a phenoloxidase-like enzyme and the array of hemocyanin-derived immune responses documented to date.

Keywords: Hemocyanin; Hemoglobin; Innate immunity; Microbicidal; Multifunctional; Phenoloxidase.

Publication types

  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antimicrobial Cationic Peptides / chemistry
  • Antimicrobial Cationic Peptides / physiology
  • Arthropod Proteins / chemistry
  • Arthropod Proteins / physiology
  • Copper / chemistry
  • Enzyme Activation
  • Hemocyanins / chemistry
  • Hemocyanins / physiology*
  • Humans
  • Immunity, Innate*
  • Models, Molecular
  • Molecular Sequence Data
  • Monophenol Monooxygenase / chemistry
  • Monophenol Monooxygenase / physiology
  • Protein Conformation


  • Antimicrobial Cationic Peptides
  • Arthropod Proteins
  • Copper
  • Hemocyanins
  • Monophenol Monooxygenase