Presence of D-alanine in proteins of normal and Alzheimer human brain.
This report constitutes the first demonstration of the presence of D-alanine in the proteins of the human nervous system. Proteins of the frontal lobe white and gray matter of human brains, both normal and Alzheimer subjects, contain D-alanine at concentrations between 0.50 and 1.28 mumol/g of wet tissue, 50-70-times lower than the concentration of L-alanine. Both white and gray matter of Alzheimer brains contain D-alanine 1.4-times higher than the respective regions of normal brains. The gray matter proteins of Alzheimer brains show a highly significant 8% decrease in total alanine content, when compared with normal brain gray matter proteins. Since Alzheimer's disease is exhibited by deterioration of the gray matter, the occurrence of elevated D-alanine levels in the gray matter of Alzheimer brains is a significant discovery and raises the question whether this enantiomer causes the degeneration of the gray matter proteins in Alzheimer's disease, or whether it is an effect of the disease.
D'Aniello
A
A
Department of Biochemistry, Stazione Zoologica A. Dohrn Villa Comunale, Naples, Italy.
Vetere
A
A
Fisher
G H
GH
Cusano
G
G
Chavez
M
M
Petrucelli
L
L
D000368:Aged; D000369:Aged, 80 and over; D000409:Alanine / Q000737:chemistry / Q000378:metabolism*; D000544:Alzheimer Disease / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D006801:Humans; D008722:Methods; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009994:Osmolar Concentration; D012016:Reference Values; D013237:Stereoisomerism; D014018:Tissue Distribution
D009419:Nerve Tissue Proteins; D000409:Alanine