Abstract
The time dependency of the spontaneous aggregation of the fibrillogenic β-Amyloid peptide, Aβ1–40, was measured by turbidity, circular dichroism, HPLC, and fluorescence polarization. The results by all methods were comparable and they were most consistent with a kinetic model where the peptide first slowly forms an activated monomeric derivative (AM), which is the only species able to initiate, by tetramerization, the formation of linear aggregates. The anti-Aβ antibody 6E10, raised against residues 1–17, at concentrations of 200–300 nM delayed significantly the aggregation of 50 μM amyloid peptide. The anti–Aβ antibody 4G8, raised against residues 17–24, was much less active in that respect, while the antibody A162, raised against the C-terminal residues 39–43 of the full-length Aβ was totally inactive at those concentrations. Concomitant with the aggregation experiments, we also measured the time dependency of the Aβ1–40–induced toxicity toward SH-EP1 cells and hippocampal neurons, evaluated by SYTOX Green fluorescence, lactate dehydrogenase release, and activation of caspases. The extent of cell damage measured by all methods reached a maximum at the same time and this maximum coincided with that of the concentration of AM. According to the kinetic scheme, the latter is the only transient peptide species whose concentration passes through a maximum. Thus, it appears that the toxic species of Aβ1–40 is most likely the same transient activated monomer that is responsible for the nucleation of fibril formation. These conclusions should provide a structural basis for understanding the toxicity of Aβ1–40 in vitro and possibly in vivo.
Similar content being viewed by others
References
Anderton, B. H., Callahan, L., Coleman, P., Davies, P., Flood, D., Jicha, G. A., et al. (1998). Prog. Neurobiol. 55: 595–609.
Ainsztein, A. M., and Purich, D. L. (1994). J. Biol. Chem. 269: 28465–28471.
Brewer, G. J., and Price, P. J. (1996). Neuroreport 7: 1509–1512.
Brewer, G. J., Torricelli, J. R., Evege, E. K., and Price, P. J. (1993). J. Neurosci. Res. 35: 567–576.
Cooper, J. A., Buhle, E. L., Jr., Walker, S. B., Tsong, T. Y., and Pollard, T. D. (1983). Biochemistry 22: 2193–2202.
Cummings, J. L., White, G. L., Jones, M. W., Cooper-Blacketer, D., Marshall, V. J., Irizarry, M., et al. (1999). Nat. Neurosci. 2: 271–276.
DeGrado, W. F., Musso, G. F., Lieber, M., Kaiser, E. T., and Kézdy, F. J. (1982). Biophys. J. 37: 329–338.
Findeis, M. A., Musso, G. M., Arico-Muendel, C. C., Benjamin, H. W., Hundal, A. M., Lee, J.-J., et al. (1999). Biochemistry 38: 6791–6800.
Ghanta, J., Shen, C.-L., Kiessling, L. L., and Murphy, R. M. (1996). J. Biol. Chem. 271: 29525–29528.
Hardy, J. (1997). Trends Neurosci. 20: 154–159.
Harper, J. D., and Lansbury, P. T., Jr. (1997). Annu. Rev. Biochem. 66: 385–407.
Hartley, D. M., Walsh, D. M., Ye, C. P., Diehl, T., Vasquez, S., Vassilev, P. M., et al. (1999). J. Neurosci. 19: 8876–8884.
Holmes, D. F., Chapman, J. A., Prockop, D. J., and Kadler, K. E. (1992). Proc. Natl. Acad. Sci. USA 89: 9855–9859.
Hsia, A. Y., Masliah, E., McConologue, G., Yu, G.-Q., Tatsuno, G., Hu, K., et al. (1999). Proc. Natl. Acad. Sci. USA 96: 3228–3233.
Jarrett, J. T., Berger, E. P., and Lansbury, P. T., Jr. (1993). Biochemistry 32: 4693–4697.
Kaiser, E. T., and Kézdy, F. J. (1984). Science 223: 249–255.
Kayed, R., Bernhagen, J., Greenfield, N., Sweimeh, K., Brunner, H., Voelter, W., et al. (1999). J. Mol. Biol. 287: 781–796.
Lambert, M. P., Barlow, A. K., Chromy, B. A., Edwards, C., Freed, R., Liosatos, M., et al. (1998). Proc. Natl. Acad. Sci. USA 95: 6448–6453.
Lomakin, A., Chung, D. S., Benedek, G. B., Kirschner, D. A., and Teplow, D. B. (1996). Proc. Natl. Acad. Sci. USA 93: 1125–1129.
Naiki, H., and Nakakuki, K. (1996). Lab. Invest. 74: 374–382.
Pallitto, M. M., Ghanta, J., Heinzelman, P., Kiessling, L. L., and Murphy, R. M. (1999). Biochemistry 38: 3570–3578.
Pallitto, M. M., and Murphy, R. M. (2001). Biophys. J. 81: 1805–1822.
Pike, C. J., Burdick, D., Walencewicz, A. J., Glabe, C. G., and Cotman, C. W. (1993). J. Neurosci. 13: 1676–1687.
Pillot, T., Drouet, B., Quielle, S., Labeur, C., Vandekerckhove, J., Rosseneu, M., et al. (1999). J. Neurochem. 73: 1626–1639.
Tobacman, L. S., and Korn, E. D. (1983). J. Biol. Chem. 258: 3207–3214.
Voter, W. A., and Erickson, H. P. (1984). J. Biol. Chem. 259: 10430–10438.
Walsh, D. M., Hartley, D. M., Kusumoto, Y., Fezoui, Y., Condron, M. M., Lomakin, A., et al. (1999). J. Biol. Chem. 274: 25945–25952.
Zhu, Y. J., Lin, H., and Ratneshwar, L. (2000). FASEB J. 14: 1244–1254. —-
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Taylor, B.M., Sarver, R.W., Fici, G. et al. Spontaneous Aggregation and Cytotoxicity of the β-Amyloid Aβ1–40: A Kinetic Model. J Protein Chem 22, 31–40 (2003). https://doi.org/10.1023/A:1023063626770
Published:
Issue Date:
DOI: https://doi.org/10.1023/A:1023063626770