Characterization and cellular localization of hemocyanin in Oniscus asellus L., a terrestrial isopod

Edward J Rappa, Fordham University


In characterizing the hemocyanin of O. asellus it was found to be similar to that of other arthropods, including isopods, in its molecular architecture, molecular weight, subunit heterogeneity and amino acid composition. Early in the investigation it was determined that commercially purchased anti-keyhole limpet (Megathura crenulata) hemocyanin cross reacted with O. asellus hemocyanin. This then allowed the use of the anti-keyhole limpet hemocyanin in subsequent immunological experiments with O. asellus hemocyanin to locate sites of hemocyanin. Using Western blot following SDS/PAGE, hemocyanin was located in the hepatopancreas and in different regions of the hindgut. Once this was established post-embedding protein A-gold immunolabeling was used to locate more specific sites of hemocyanin. Protein A-gold immunolabeling demonstrated the presence of hemocyanin in the granules of the granulocytes associated with the heart. Label was noted in the cisternae of the rough endoplasmic reticulum and in the cuprosomes or copper storage bodies in S cells and in single membrane bound vesicles and residual bodies in B cells of the hepatopancreas. The label was also noted in the area of the plasmalemma of the basal infoldings of the epithelial cells in the papillate region of the hindgut. A densitometric analysis revealed that almost 60% of protein A-gold particles were located within 15 nm of the plasmalemma. This interaction of hemocyanin with a natural biomembrane might be important in oxygen exchange in invertebrates with an open circulatory system.

Subject Area

Cellular biology|Zoology

Recommended Citation

Rappa, Edward J, "Characterization and cellular localization of hemocyanin in Oniscus asellus L., a terrestrial isopod" (1994). ETD Collection for Fordham University. AAI9425203.