Quaternary and tertiary structure of haemerythrin

THE oligomeric protein haemerythrin is an oxygen-transport pigment found in erythrocytes of the coelomic fluid of certain invertebrates. It usually occurs as an octamer of molecular weight 108,000, in which each sub-unit contains two Fe atoms and reversibly binds one O2 molecule1. There is convincing evidence that myohaemerythrin, a monomeric protein found in the retractor muscles of the sipunculan worm Themiste pyroides, and the protomers of...