TY - JOUR
T1 - Biochemical and immunological characterization of neurofilaments in experimental neurofibrillary degeneration induced by aluminum
AU - Selkoe, Dennis J.
AU - Liem, Ronald K.H.
AU - Yen, Shu Hui
AU - Shelanski, Michael L.
N1 - Funding Information:
We wish to thank Ms. Carol Van Horn for her expert assistance in electron microscopy and Ms. Alice Magnet for valuable assistance in all aspects of this study. The work was supported by N.I.H. Grants AG00704, NS11504 and a grant from the McKnight Foundation. Dr. Selkoe is the recipient of the Whittier Fellowship of the Committee to Combat Huntington's Disease.
PY - 1979/3/16
Y1 - 1979/3/16
N2 - In order to identify the protein composition of 10 nm neuronal filaments, we prepared enriched fractions of rabbit spinal neurons undergoing experimental neurofilamentous degeneration induced by aluminum. Electron microscopy of the isolated perikarya showed well-preserved, large perinuclear masses of neurofilaments, which were not found in similarly isolated control perikarya. Comparison of these glial-free fractions by SDS-polyacrylamide gel electrophoresis revealed several-fold augmentation in the filament-enriched neurons of proteins migrating at 68,000 and 160,000 daltons, with an additional component at 200,000 daltons. Otherwise, the protein patterns were identical; no band was found at 51,000 daltons, the molecular weight assigned to the major proteins both of glial filaments and of a previously reported bovine brain filament preparation. An antiserum raised against the 160,000 dalton component of a modified bovine brain filament fraction produced specific and intense fluorescent staining of the aluminum-induced neurofilament bundles. Antibodies to the 51,000 dalton protein of brain filaments and to tubulin failed to stain the induced filaments. The results strongly support the hypothesis that both normal and aluminum-induced neuronal filaments are composed of 68,000, 160,000 and 200,000 dalton polypeptides and do not contain significant amounts of the 51,000 dalton filament protein. The likelihood of biochemical heterogeneity among organelles with similar morphology, namely the glial and neuronal filaments, is raised.
AB - In order to identify the protein composition of 10 nm neuronal filaments, we prepared enriched fractions of rabbit spinal neurons undergoing experimental neurofilamentous degeneration induced by aluminum. Electron microscopy of the isolated perikarya showed well-preserved, large perinuclear masses of neurofilaments, which were not found in similarly isolated control perikarya. Comparison of these glial-free fractions by SDS-polyacrylamide gel electrophoresis revealed several-fold augmentation in the filament-enriched neurons of proteins migrating at 68,000 and 160,000 daltons, with an additional component at 200,000 daltons. Otherwise, the protein patterns were identical; no band was found at 51,000 daltons, the molecular weight assigned to the major proteins both of glial filaments and of a previously reported bovine brain filament preparation. An antiserum raised against the 160,000 dalton component of a modified bovine brain filament fraction produced specific and intense fluorescent staining of the aluminum-induced neurofilament bundles. Antibodies to the 51,000 dalton protein of brain filaments and to tubulin failed to stain the induced filaments. The results strongly support the hypothesis that both normal and aluminum-induced neuronal filaments are composed of 68,000, 160,000 and 200,000 dalton polypeptides and do not contain significant amounts of the 51,000 dalton filament protein. The likelihood of biochemical heterogeneity among organelles with similar morphology, namely the glial and neuronal filaments, is raised.
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U2 - 10.1016/0006-8993(79)90352-4
DO - 10.1016/0006-8993(79)90352-4
M3 - Article
C2 - 371751
AN - SCOPUS:0018397187
SN - 0006-8993
VL - 163
SP - 235
EP - 252
JO - Brain Research
JF - Brain Research
IS - 2
ER -