Glutamine synthetase in experimental meningitis: increased ratio of the subunits 3 and 2 may indicate enhanced activity.
Glutamine synthetase (GS) activity is higher in the neocortex but not in the hippocampal formation of rabbit brain during Streptococcus pneumoniae meningitis compared to the respective brain region of uninfected control animals. One-dimensional polyacrylamide gel electrophoresis (1D-SDS-PAGE) revealed an apparent molecular mass (M(r)) of 44000 Dalton (Da) for GS from rabbit brain. After two-dimensional gel electrophoresis (2D-PAGE), followed by Coomassie-blue staining, GS separated into three distinct spots (S1, S2, S3). One additional spot (S4) occurred on the immunoblot. All four GS spots exhibited the same M(r) (44000 Da), but differed in their isoelectric points. Densitometric evaluation of the two-dimensional maps revealed a strong increase of optical density (OD) of S3 in the frontal cortex of infected animals. The calculated OD ratio S3/S2 in the frontal cortex from rabbits with meningitis was 1.75+/-0.68 (mean+/-standard deviation). Compared to controls (0. 85+/-0.39), this value was significantly increased (p=0.0006). In the hippocampal formation, the ratio S3/S2 was nearly unchanged during meningitis. It is suggested that the ratio S3/S2 may indicate a neuroprotective feature of rabbit brain during meningitis since neuronal apoptosis occurs only in the dentate gyrus and not in the frontal cortex.
Smirnov
A V
AV
Department of Neurology, University of Gottingen, Robert-Koch-Strasse 40, D-37075, Göttingen, Germany.
Tumani
H
H
Henne
S
S
Barchfeld
S
S
Olgemöller
U
U
Wiltfang
J
J
Lange
P
P
Mäder
M
M
Nau
R
R
D000818:Animals; D017209:Apoptosis; D015180:Electrophoresis, Gel, Two-Dimensional; D005974:Glutamate-Ammonia Ligase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006624:Hippocampus / Q000201:enzymology / Q000473:pathology; D007526:Isoelectric Point; D008586:Meningitis, Pneumococcal / Q000201:enzymology* / Q000473:pathology; D008970:Molecular Weight; D019579:Neocortex / Q000201:enzymology / Q000473:pathology; D020836:Protein Structure, Quaternary; D011817:Rabbits; D014018:Tissue Distribution
D005974:Glutamate-Ammonia Ligase