S. Aime et al., EVIDENCE FOR A GLYCIDIC-LIPIDIC MATRIX IN HUMAN NEUROMELANIN, POTENTIALLY RESPONSIBLE FOR THE ENHANCED IRON SEQUESTERING ABILITY OF SUBSTANTIA-NIGRA, Journal of neurochemistry, 62(1), 1994, pp. 369-371
The high-resolution solid-state C-13-NMR spectrum of a neuromelanin sp
ecimen (from patients dying from nonneurological diseases) is compared
with that obtained from enzymatically prepared dopamine-melanin, The
main differences between the two spectra suggest the occurrence in neu
romelanin of a glycidic/lipidic matrix tightly associated with the mel
anin macromolecule. Atomic emission spectroscopy revealed high iron co
ntent (1.5%) in the neuromelanin specimen, in full agreement with prev
ious reports. These observations support the view that neuromelanin ac
ts as a strong chelating (and insolubilizing) system for iron ions and
further suggest that the attack to this compact composite substrate m
ay be an important step to allow the release of iron ions responsible
for the increased lipid peroxidation reported in the pathogenesis of P
arkinson's disease.