Kinetic studies on the glutamate:glyoxylate transaminase of Euglena gracilis
The kinetic properties of L-glutamate:glyoxylate transminase have been investigated. Glycine formation was linear with both protein concentration and incubation time. L-glutamate was the most effective amino donor. Optimal concentrations for L-glutamate and glyoxylate were 150-200 mM and 10-20 mM, r...
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todo:paper_10111344_v36_n3_p241_Lombardo2023-10-03T15:56:13Z Kinetic studies on the glutamate:glyoxylate transaminase of Euglena gracilis Lombardo, M.E. Araujo, L.S. Del C. Batlle, A.M. 5-aminolevulinic acid biosynthesis Euglena gracilis Glutamate:4,5-dioxovalerate trasaminase Glutamate:glyoxylate transaminase aminotransferase glutamic acid glycine glyoxylic acid valeric acid derivative article controlled study enzyme inhibition enzyme kinetics enzyme mechanism enzyme substrate complex euglena gracilis nonhuman priority journal transamination The kinetic properties of L-glutamate:glyoxylate transminase have been investigated. Glycine formation was linear with both protein concentration and incubation time. L-glutamate was the most effective amino donor. Optimal concentrations for L-glutamate and glyoxylate were 150-200 mM and 10-20 mM, respectively. Initial velocity studies suggested a ping-pong reaction mechanism with a K(m) value of 89.90-66.50 mM for L-glutamate and of 12.50-10.75 mM for glyoxylate. A competitive parabolic substrate inhibition by glyoxylate at concentrations greater than 20 mM was observed. A pure linear non-competitive inhibition between glyoxylate and 4,5-dioxovaleric acid (1.1-2.8 mM) was found. We show here that in vivo different enzymes exist for the transamination of glyoxylate and DOVA. Fil:Lombardo, M.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Araujo, L.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Del C. Batlle, A.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_10111344_v36_n3_p241_Lombardo |
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Universidad de Buenos Aires |
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I-28 |
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R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
5-aminolevulinic acid biosynthesis Euglena gracilis Glutamate:4,5-dioxovalerate trasaminase Glutamate:glyoxylate transaminase aminotransferase glutamic acid glycine glyoxylic acid valeric acid derivative article controlled study enzyme inhibition enzyme kinetics enzyme mechanism enzyme substrate complex euglena gracilis nonhuman priority journal transamination |
| spellingShingle |
5-aminolevulinic acid biosynthesis Euglena gracilis Glutamate:4,5-dioxovalerate trasaminase Glutamate:glyoxylate transaminase aminotransferase glutamic acid glycine glyoxylic acid valeric acid derivative article controlled study enzyme inhibition enzyme kinetics enzyme mechanism enzyme substrate complex euglena gracilis nonhuman priority journal transamination Lombardo, M.E. Araujo, L.S. Del C. Batlle, A.M. Kinetic studies on the glutamate:glyoxylate transaminase of Euglena gracilis |
| topic_facet |
5-aminolevulinic acid biosynthesis Euglena gracilis Glutamate:4,5-dioxovalerate trasaminase Glutamate:glyoxylate transaminase aminotransferase glutamic acid glycine glyoxylic acid valeric acid derivative article controlled study enzyme inhibition enzyme kinetics enzyme mechanism enzyme substrate complex euglena gracilis nonhuman priority journal transamination |
| description |
The kinetic properties of L-glutamate:glyoxylate transminase have been investigated. Glycine formation was linear with both protein concentration and incubation time. L-glutamate was the most effective amino donor. Optimal concentrations for L-glutamate and glyoxylate were 150-200 mM and 10-20 mM, respectively. Initial velocity studies suggested a ping-pong reaction mechanism with a K(m) value of 89.90-66.50 mM for L-glutamate and of 12.50-10.75 mM for glyoxylate. A competitive parabolic substrate inhibition by glyoxylate at concentrations greater than 20 mM was observed. A pure linear non-competitive inhibition between glyoxylate and 4,5-dioxovaleric acid (1.1-2.8 mM) was found. We show here that in vivo different enzymes exist for the transamination of glyoxylate and DOVA. |
| format |
JOUR |
| author |
Lombardo, M.E. Araujo, L.S. Del C. Batlle, A.M. |
| author_facet |
Lombardo, M.E. Araujo, L.S. Del C. Batlle, A.M. |
| author_sort |
Lombardo, M.E. |
| title |
Kinetic studies on the glutamate:glyoxylate transaminase of Euglena gracilis |
| title_short |
Kinetic studies on the glutamate:glyoxylate transaminase of Euglena gracilis |
| title_full |
Kinetic studies on the glutamate:glyoxylate transaminase of Euglena gracilis |
| title_fullStr |
Kinetic studies on the glutamate:glyoxylate transaminase of Euglena gracilis |
| title_full_unstemmed |
Kinetic studies on the glutamate:glyoxylate transaminase of Euglena gracilis |
| title_sort |
kinetic studies on the glutamate:glyoxylate transaminase of euglena gracilis |
| url |
http://hdl.handle.net/20.500.12110/paper_10111344_v36_n3_p241_Lombardo |
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