Biosynthesis of D-aspartate in mammalian cells.
In this communication, we demonstrate that D-aspartate (D-Asp) is synthesized in pheochromocytoma cells (PC12). To our knowledge this is the first report of biosynthesis of D-Asp in mammalian cells. Synthesis of D-Asp was demonstrated by its time-dependent accumulation in the cell culture, and by the fact that this accumulation was proportional to the number of inoculated cells. D-Asp in PC12 cells was identified by (i) co-elution with authentic D-Asp on two different HPLC columns, an octadesyl silica column and a Pirkle-type chiral column, (ii) reversed elution order of D-Asp and L-Asp on another Pirkle-type chiral column with an opposite configuration, and (iii) sensitivity to D-Asp oxidase. In the cells the amount of D-Asp was approx. 12-14% of total Asp and no other investigated D-amino acid was detected. The amount of D-Asp did not increase during the culture of mouse 3T3 fibroblasts and human neuroblastoma NB-1 cells. Immunocytochemical staining with anti-D-Asp antiserum demonstrated that D-Asp synthesized is present in the cytoplasm of the cells.
Long
Z
Z
Graduate School of Pharmaceutical Sciences, University of Tokyo, Japan.
Homma
H
H
Lee
J A
JA
Fukushima
T
T
Santa
T
T
Iwatsubo
T
T
Yamada
R
R
Imai
K
K
D016475:3T3 Cells; D000818:Animals; D001224:Aspartic Acid / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D003593:Cytoplasm / Q000737:chemistry; D006801:Humans; D051379:Mice; D016716:PC12 Cells; D051381:Rats; D013237:Stereoisomerism; D014407:Tumor Cells, Cultured
D001224:Aspartic Acid