Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.4.1.2 (
glutamate dehydrogenase
)
4,380
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
A crude mitochondrial fraction (M) derived from manually disrupted cerebellar tissue and enriched in
choline acetyltransferase
(
ChAT
) activity was fractionated by centrifugation in discontinuous and continuous sucrose gradients. Further purification of 'cholinergic' synaptosomes was achieved (relative specific activity (RSA) of
ChAT
greater than 3), but the overlap with other synaptosomal populations was still considerable. Hand-homogenized cerebella processed through the full fractionation procedure described here and in previous papers yielded preparations enriched in certain neuronal structures and a fraction in which 'heavy' free mitochondria was concentrated. To characterize these preparations the activities of two transmitter enzymes (CHAT and glutamate decarboxylase, GAD) and 6 mitochondrial enzymes (succinate dehydrogenase (SDH),
glutamate dehydrogenase
(
GDH
), monoamine oxidase, citrate synthase, fumarase and GABA-aminotransferase) were determined. The distribution of the transmitter enzymes was clearly different in the preparations containing various neuronal structures. The GAD:
ChAT
RSA ratio was 2.4 for the glomerulus particles, 1.3 for the molecular layer fragments, 0.6 for the myelinated axon segments, and 0.2 for the 'cholinergic' synaptosomes. The mitochondrial enzyme profile of the preparations comprising mainly neuronal structures differed markedly from that of the 'free' mitochondrial fraction. Notably the latter was greatly enriched in
GDH
(RSA 5.6), whereas the SDH:
GDH
RSA ratio was relatively high in the former preparations. Nevertheless there were notable differences in the enzyme profile of the fractions of predominantly neuronal origin indicating that the enzyme composition of mitochondria of neuronal processes is not uniform.
...
PMID:Subcellular fractionation of rat cerebellum: separation of synaptosomal populations and heterogeneity of mitochondria. 21 84
By a combination of differential and sucrose density gradient (both discontinuous and linear) centrifugation, large fragments of the cerebellar glomeruli were isolated in high purity from hand homogenised tissue. The final preparation contained only about 1% of the tissue protein, but over 90% of its volume was accounted for by the glomerulus particles. The ultrastructure of the glomerulus particles was well preserved. The enzyme profile was characteristic: the glomerulus particles were enriched in glutamate decarboxylase (GAD) activity (relative specific activity (RSA), 2.54), but the RSA of
choline acetyltransferase
(ChAc) was only 1.05. These findings are consistent with the view that GAD activity is very high in the inhibitory Golgi terminals, which occupy only a small fraction of the total volume of the particles, and acetylcholine may be a transmitter only in a relatively small fraction of the mossy fibre terminals. The glomerulus particles also contained a high concentration of succinate dehydrogenase (SDH) activity (RSA, 1.91), whereas the RSA of
glutamate dehydrogenase
(
GDH
) was only 1.15. The great asset of this preparation for future investigations is that it is composed almost exclusively from pre- and postsynaptic neuronal structures. Fractions containing neuropil fragments of non-glomerular origin were also obtained, but the profile of the estimated enzymes did not indicate unique characteristics.
...
PMID:Subcellular fractionation of rat cerebellum: an electron microscopic and biochemical investigation. III. Isolation of large fragments of the cerebellar glomeruli. 111 92
