Abstract
We report here the isolation of fractions enriched in components of the myelin-like membranes surrounding the giant axons of the earthworm.Lumbricus terrestris L. The composition and purity of the fractions have been assessed using SDS-protein electrophoresis, Western immunoblots, and electron microscopy. Preliminary enzyme assays indicated that the mitochondrial marker, succinate dehydrogenase, has a similar specific activity distribution in earthworm nerve cord and in mouse liver sedimentation velocity fractions, however, the distribution of the total units of activity among the fractions seems to indicate the existence of smaller mitochondria in earthworm nerve cord compared with mouse liver mitochondria. In earthworm nerve cord fractions, Na+/K+ ATPase and Ca2+/Mg2+ ATPase were found to be enriched exclusively in the fraction containing large plasma and myelin-like membranes, while in the mouse liver fractions, the total units of these two enzymes were found to be distributed broadly among fractions. 5′-Nucleotidase activity in the earthworm nerve cord seemed to be restricted to the microsomal fractions (endomembrane network), with a very low activity associated with the large plasma and myelin-like membrane fraction. We have established the presence of keratins or prekeratins in the myelin-like membranes, probably in the form of tonofilaments. However, we could not show that the desmosome-like structures, characteristic of these membranes, are composed of those proteins described for vertebrate epithelial desmosomes.
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Avruch, J., and Wallach, D. F. H. 1971. Preparation and properties of plasma membrane and endoplasmic reticulum fragments from isolated rat fat cells. Biochim. Biophys. Acta 223:334–347.
Coggeshall, R. E. 1966. A fine structural analysis of the ventral nerve cord and associated sheath ofLumbricus terrestris L. J. Comp. Neurol. 125:393–438.
Colaco, C. A., and Evans, W. H. 1982. Partial purification of an intercalated disc-containing cardiac plasma membrane fraction. Biochim. Biophys. Acta. 684:40–46.
Earl, D. C. N., and Korner, A. 1965. The isolation and properties of cardiac ribosomes and polysomes. Biochem. J. 94:721–734.
Franke, W. W., Schmid, E., Grund, Ch., Müller, H., Engelbrecht, I., Moll, R., Stadler, J., and Jarasch, E. D. 1981. antibodies to high molecular weight polypeptides of desmosomes: Specific localization of a class of junctional proteins in cells and tissues. Differentiation 20:217–241.
Gorbsky, G., and Steinberg, M. S. 1981. Isolation of the intercellular glycoproteins of desmosomes. J. Cell Biol. 90:243–248.
Green, C. R., Noirot-Timothe, C., and Noirot, C. 1983. Isolation and characterization of invertebrate smooth septate junctions. J. Cell Sci. 62:351–370.
Guenther, J. 1976. Impulse conduction in the myelinated giant fibers of the Earthworm. Structure and function of the dorsal nodes in the median giant fiber. J. Comp. Neurol. 168:505–532.
Hama, K. 1959. Some observations on the fine structure of the giant nerve fibers of the earthworm,Eisenia foetida. J. Biophys. Biochem. Cytol. 6:61–66.
Heuser, J. E., and Doggenweiler, C. F. 1966. The fine structural organization of nerve fibers, sheaths, and glial cells in the prawn,Palaemonetes vulgaris. J. Cell Biol. 30:381–403.
Levi, J. U., Cowden, R. R., and Collins, G. H. 1966. The microscopic anatomy and ultrastructure of the nervous system in the earthworm (lumbricus sp.) with emphasis on the relationship between glial cells and neurons. J. Comp. Neurol. 127:489–510.
Okemura, N., Stoskopf, M., Hendricks, F., and Kishimoto Y. 1985. Lipid composition of the nervous system of earthworms (Lumbricus terrestris). J. Neurochem. 45:1875–1879.
Okemura, N., Yamaguchi, H., Stoskopf, M., Kishito, Y., and Saida, T. 1986. Isolation and characterization of multilayered sheath membrane rich in glucocerebroside from shrimp ventral nerve. J. Neurochem. 47:1111–1116.
Pereyra, P. M., and Braun, P. E. 1983. Studies on subcellular fractions which are involved in myelin membrane assembly: isolation from developing mouse brain and characterization by enzyme markers, electron microscopy, and electrophoresis. J. Neurochem. 41:957–973.
Roots, B. I., and Lane, N. J. 1983. Myelinating glia of earthworm giant axons: Thermally induced intramembranous changes. Tissue & Cell 15:695–709.
Slack, J. R., Anderson, B. H., and Day, W. A. 1973. Biochim. Biophys. Acta 232:547–559.
Solyom, A., and Trams, E. G. 1972. Enzyme markers for the characterization of isolated plasma membranes. Enzymes 13:329–372.
Spray, D. C., and Bennett, M. V. 1985. Physiology and pharmacology of gap junctions. Annu. Rev. Physiol. 47:281–303.
Warren, G. B., Toon, P. A., Birdsall, N. J. M., Lee, A. G., and Metcalfe, J. C. 1974. Reconstitution of a calcium pump using membrane components. Proc. Natl. Acad. Sci. USA 71:622–626.
Zervos, A. S., Hope, J., and Evans, W. H. 1985. Preparation of a gap junction fraction from the uteri of pregnant rats: The 28-KD polypeptides of uterus, liver, and heart gap junctions are homologous. J. Cell Biol. 101:1363–1370.
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Pereyra, P.M., Roots, B.I. Isolation and initial characterization of myelin-like membrane fractions from the nerve cord of earthworms (Lumbricus terrestris L). Neurochem Res 13, 893–901 (1988). https://doi.org/10.1007/BF00970759
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DOI: https://doi.org/10.1007/BF00970759