In vitro binding of [14C]2,5-hexanedione to rat neuronal cytoskeletal proteins.
2,5-Hexanedione (2,5-HD) induces central-peripheral axonpathy characterized by the accumulation of 10-nm neurofilaments proximal to the nodes of Ranvier and a Wallerian-type degeneration. It has been postulated that neurofilament crosslinking may be involved in the production of this axonopathy. A potential initiating event in this neurotoxic process may be the direct binding of 2,5-HD to neurofilament and microtubule proteins. In this study, the in vitro binding of [14C]2,5-HD to neurofilament and microtubule proteins was examined. Neurofilament proteins isolated from rat spinal cord or microtubule proteins isolated from rat brain were incubated in the presence of 2,5-HD at concentrations ranging from 25 to 500 mM. Quantitative analysis of sodium dodecyl sulfate (SDS) polyacrylamide gels revealed a dose- and time-dependent binding of 2,5-HD to both neurofilament proteins and microtubule proteins. Expressed as pmol 2,5-HD bound per microgram protein, the observed relative binding was MAP2 > NF160 > NF200 > > NF68 > tubulin. These data demonstrate the direct binding of 2,5-HD to cytoskeletal proteins including both neurofilaments and microtubules.
Lanning
C L
CL
Department of Pharmacology, Duke University Medical Center, Durham, North Carolina 27710.
Wilmarth
K R
KR
Abou-Donia
M B
MB
D000818:Animals; D002250:Carbon Radioisotopes; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D006588:Hexanones / Q000378:metabolism*; D015151:Immunoblotting; D008297:Male; D008868:Microtubule Proteins / Q000378:metabolism*; D016900:Neurofilament Proteins / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D010084:Oxidation-Reduction; D011758:Pyrroles / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley
D002250:Carbon Radioisotopes; D003598:Cytoskeletal Proteins; D006588:Hexanones; D008868:Microtubule Proteins; D016900:Neurofilament Proteins; D011758:Pyrroles; C091499:1-(2-hydroxyethyl)-2,5-dimethylpyrrole; C011269:2,5-hexanedione