Abstract
Using the immunoblot technique, we found that an incubation of purified human myelin in 10 mM Tris-HCl buffer at pH 7.5 resulted in the conversion of the myelinassociated glycoprotein (MAG) to a smaller derivative (dMAG). Exogenously added 5 mM CaCl2 accelerated the conversion of MAG. In buffer containing more than 100 μM of EGTA, the conversion was inhibited. In addition, the existence of endogenous calcium in purified myelin was confirmed using atomic absorption spectroscopy. The conversion was also inhibited partially by one of the thiol protease inhibitors, E-64 analogue (E-64-a). These observations suggest that the conversion of MAG is mediated by calcium-activated neutral protease (CANP)-like enzyme.
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Quarles, R. H., Everly, J. L., andBrady, R. O. 1973. Evidence for the close association of a glycoprotein with myelin in rat brain. J. Neurochem. 21:1177–1191.
Figlewicz, D. A., Quarles, R. H., Johnson, D., Barbarash, G. R., andSternberger, N. H. 1981. Biochemical demonstration of the myelin-associated glycoprotein in the peripheral nervous system. J. Neurochem. 37:749–758.
Sato, S., Quarles, R. H., andBrady, R. O. 1982. Susceptibility of the myelin-associated glycoprotein and basic protein to a neutral protease in highly purified myelin from human and rat brain. J. Neurochem. 39:97–105.
Itoyama, Y., Sternberger, N. H., Webster, H. deF., Quarles, R. H., Cohen, S. R., andRichardson, E. P., Jr. 1980. Immunocytochemical observations on the distribution of myelin-associated glycoprotein and myelin basic protein in multiple sclerosis lesions. Ann. Neurol. 7:167–177.
Johnson, D., Sato, S., Quarles, R. H., Brady, R. O., andWebster, H. deF. 1981. Radioimmunoassay for the myelin-associated glycoprotein in multiple sclerosis brain. J. Neuropathol. Exp. Neurol. 40:308.
Sato, S., Quarles, R. H., Brady, R. O., andTourtellotte, W. W. Elevated neutral protease activity in myelin from multiple sclerosis brains. Ann. Neurol. in press.
Tamai, M., Hanada, K., Adachi, T., Oguma, K., Kashiwagi, K., Omura, S., andOhzeki, M. 1981. Papain inhibitions by optically active E-64 analogs. J. Biochem. 90:255–257.
Norton, W. T., andPoduslo, S. E. 1973. Myelination in rat brain: Method of myelin isolation. J. Neurochem. 21:749–757.
Quarles, R. H., andPasnak, C. F. 1977. A rapid procedure for selectively isolating the major glycoprotein from purified rat brain myelin. Biochem. J. 163:635–637.
Barbarash, G. R., Figlewicz, D. A., andQuarles, R. H. 1981. Myelin-associate glycoprotein: Purification and partial characterization. Trans. Am. Soc. Neurochem. 12:165.
Sato, S., andMiyatake, T. 1982. Degradation of myelin basic protein by calcium-activated neutral protease (CANP)-like enzyme in myelin and inhibition by E-64 analogue. Biomedical. Res. 3:461–464.
Laemmli, U. K., andFavre, M. 1973. Maturation of the head of bacteriophage T4. I. DNA packaging events. J. Mol. Biol. 80:575–599.
Towbin, H., Staehelin, T., andGordon, J. 1979. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: Procedure and some applications. Proc. Natl. Acad. Sci., U.S.A. 76:4350–4354.
Sato, S., Baba, H., Tanaka, M., Yanagisawa, K., andMiyatake, T., 1983. Antigenic determinant shared between myelin-associated glycoprotein from human brain and natural killer cells. Biomedical Res. 4:489–494.
Hanada, K., Tamai, M., Yamagishi, M., Ohmura, S., Sawada, J., andTanaka, I. 1978. Isolation and characterization of E-64, a new thiol protease inhibitor. Agric. Biol. Chem. 42:523–528.
Yanagisawa, K., Sato, S., Amaya, N., andMiyatake, T., 1983. Degradation of myelin basic protein by calcium-activated neutral protease (CANP) in human brain and inhibition by E-64 analogue. Neurochem. Res. 8:1285–1293.
Sternberger, N. H., Quarles, R. H., Itoyama, Y., andWebster, H. deF. 1979. Myelin-associated glycoprotein demonstrated immunocytochemically in myelin and myelin-forming cells of developing rat. Proc. Natl. Acad. Sci., U.S.A. 76:1510–1514.
Quarles, R. H. 1980. Glycoproteins from central and peripheral myelin. Pages 55–77,in Hashim, G. (ed), Myelin: Chemistry and Biology, Alan R. Liss, New York.
Trapp, B. D., andQuarles, R. H. 1982. Presence of the myelin-associated glycoprotein correlates with alterations in the periodicity of peripheral myelin. J. Cell Biol. 92:877–882.
Braun, P. E., Frail, D. E., andLatov, N. 1982. Myelin-associated glycoprotein is the antigen for a monoclonal IgM in polyneuropathy. J. Neurochem. 39:1261–1265.
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Sato, S., Yanagisawa, K. & Miyatake, T. Conversion of myelin-associated glycoprotein (MAG) to a smaller derivative by calcium activated neutral protease (CANP)-like enzyme in myelin and inhibition by E-64 analogue. Neurochem Res 9, 629–635 (1984). https://doi.org/10.1007/BF00964509
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DOI: https://doi.org/10.1007/BF00964509