Racemized D-aspartate in Alzheimer neurofibrillary tangles

Advanced Maillard reaction end products are associated with Alzheimer disease pathology.

“…Three other post-translational modifications, racemization (31), isomerization (32), and phosphorylation (33), have been described in association with the pathological lesions of AD. Aberrant phosphorylation of T, a major component of neurofibrillary tangles (34), is thought to precipitate protein aggregation (35).…”

Racemization: Its Biological Significance on Neuropathogenesis of Alzheimer's Disease.

“…Indeed, Shapira et al (1988) have reported that their amyloid preparations from Alzheimer's disease brains contain approximately 5% D-Asp and 2% D-Ser. Another example for the presence of pathological racemization was provided by Fisher et al (1992) who found that proteins of neurofibrillary tangles from Alzheimer's disease brains were also racemized. Recently, Roher et al (1993) have extensively examined the structure of A/3 extracted from the amyloid cores of neuritic plaques and have identified altered Asp residues: Asp residues at positions 1 and 7 represent as a mixture of normal Asp and iso-Asp isomers in both the D-and L-configurations.…”

Free D- and L-amino acids in ventricular cerebrospinal fluid from Alzheimer and normal subjects

“…However, recently, D-Asp has been found in Alzheimer brain neurofibrillary tangles (Fisher et al, 1992a), and high levels of D-Asp and DAla have been found in proteins of white and gray matter of Alzheimer brain (Fisher et al, 1992b;D'Aniello et al, 1992). In both these cases, the level of these D-amino acids was higher in the Alzheimer brains than in normal brains.…”