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Glutamate Dehydrogenase in Human Brain: Regional Distribution and Properties
Author(s) -
Filla A.,
Michele G.,
Morra V. Brescia,
Palma V.,
Lauro A.,
Geronimo G.,
Campanella G.
Publication year - 1986
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1986.tb12985.x
Subject(s) - cerebellum , endocrinology , glutamate receptor , medicine , human brain , glutamate dehydrogenase , chemistry , biology , biochemistry , receptor , neuroscience
Glutamate dehydrogenase (GDH) activity was studied in 17 regions of six human brains. Duration and conditions of the postmortem period did not affect enzyme activity. Specific activity ranged between 103 and 377 nmoles/min/mg protein at 25°C and it was 10‐fold higher than that found in leukocytes. Apart from exclusively white matter regions (corpus callosum and centrum ovale), there was a moderate regional distribution (2.5‐fold variation), with highest values in the inferior olive and hypothalamus, and lowest in the cerebellum and lenticular nucleus. With α‐ketoglutarate (α‐KG), NADH, or NH 4 + as variable substrate, the apparent K m values in human brain were K m α‐KG = 1.9 × 10 −3 M, K m NADH = 0.21 × 10 −3 M, and K m NH4+ = 28 × 10 −3 M, and in leukocytes they were K m α‐KG = 1.7 × 10 −3 M, K m NADH = 0.24 × 10 −3 M, and K m NH4+ = 28 × 10 −3 M. The effects of cofactors, inhibitor, and pH were similar in brain and leukocyte GDH.