| Autor: |
Walter, Ulrich, Luthe, Hilmar, Gerhart, Fritz, Söling, Hans-Dieter |
| Předmět: |
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| Zdroj: |
European Journal of Biochemistry; Nov75 Part 2, Vol. 59 Issue 2, p395-403, 9p |
| Abstrakt: |
The hydrogen exchange at the β-carbon of L-alanine, L-glutamate and L-aspartate with water has been examined during transamination catalyzed by glutamic-oxaloacetic transaminase and by glutamic-pyruvic transminase. A significant hydrogen exchange at the β-carbon has been demonstrated during incubation of L-[3-3H]alanine + glutamic-pyruvic transaminase, L-[3-3H]alanine - α-oxoglutarate + glutamic-pyruvic transaminase, L-[3-3H]glutamate + glutamic-oxaloacetic transaminase, L-[3-3H]glutamate + oxaloacetate + glutamic-oxaloacetic transaminase, and L-[3-3H]glutamate + pyruvate + glutamic-pyruvic tansaminase as shown by the appearance of 3H2O. No hydrogen exchange at the β-carbon of L-glutamate occurred during incubation of L-[3-3H]-glutamate with glutamic-pyruvic transminase alone. The hydrogen exchange at the β-carbon of L-glutamate coincides with transamination as demonstrated by nuclear magnetic resonance studies of 2H2O-L-glutamate exchange during transamination by glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase. No hydrogen exchange at the β-carbon occurred during transamination of L-aspartate by glutamic-oxaloacetic transaminase as shown by nuclear magnetic resonance spectroscopy and confirmed by nuclear magnetic resonance simulation studies. The results are discussed with special reference to the different equilibria between the pyridoxal form and the pyridoxamine form of glutamic-oxaloacetic transaminase and of glutamic-pyruvic transaminase. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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