Abstract:
:We used high-field (13)C NMR (18.8 T) to assign unambiguously the isotopic shifts induced by the deuterium substitutions of the H3(proR) and H3(proS) hydrogens of (2-(13)C) glutamate in extracts of the brain from deuterated animals. Monodeuterated H3R or H3S glutamate diastereoisomers were produced stereospecifically either by chemical synthesis or by coupling the reactions of isocitrate dehydrogenase and aspartate aminotransferase in deuterated medium, respectively. We show that the (3S-(2)H) or (3R-(2)H) deuterations induce characteristic small (Delta(2) = -0.058 parts per million (ppm)) or large (Delta(2) = -0.071 ppm) vicinal isotopic shifts upfield of the perprotonated (2-(13)C) glutamate resonance (at 55.5 ppm). Isotopically shifted (2-(13)C, 3S-(2)H) or (2-(13)C, 3R-(2)H) glutamate singlets are conveniently observed by high-field (13)C NMR in brain extracts from deuterated rats. Since the (3S-(2)H) or (3R-(2)H) glutamate diastereoisomers are produced stereospecifically by the cytosolic or mitochondrial isoforms of aconitase and isocitrate dehydrogenase, our results will facilitate the (13)C NMR investigation of these enzymatic activities and their role in subcellular glutamate trafficking.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Rodrigues TB,Violante IR,Cerdán Sdoi
10.1002/mrm.22277subject
Has Abstractpub_date
2010-04-01 00:00:00pages
1088-91issue
4eissn
0740-3194issn
1522-2594journal_volume
63pub_type
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