Glutamate:4,5‐dioxovaleric acid transaminase from Euglena gracilis Kinetic studies
The kinetic properties of the enzyme l‐glutamate:4,5‐dioxovaleric acid aminotransferase (Glu: DOVA transaminase) from Euglena gracilis have been studied. 5‐Aminolevulinic acid formation was linear with time for at least 45 min at 37°C and l‐glutamate was the most effective amino‐group donor. Linewea...
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todo:paper_00142956_v182_n3_p657_LOMBARDO2023-10-03T14:11:51Z Glutamate:4,5‐dioxovaleric acid transaminase from Euglena gracilis Kinetic studies LOMBARDO, M.E. ARAUJO, L.S. JUKNAT, A.A. BATLLE, A.M.d.C. aminolevulinate aminotransferase aminotransferase animal article darkness enzyme specificity enzyme stability enzymology Euglena gracilis growth, development and aging isolation and purification kinetics Animal Darkness Enzyme Stability Euglena gracilis Kinetics Substrate Specificity Support, Non-U.S. Gov't Transaminases The kinetic properties of the enzyme l‐glutamate:4,5‐dioxovaleric acid aminotransferase (Glu: DOVA transaminase) from Euglena gracilis have been studied. 5‐Aminolevulinic acid formation was linear with time for at least 45 min at 37°C and l‐glutamate was the most effective amino‐group donor. Lineweaver‐Burk double‐reciprocal plots suggested a ping‐pong reaction mechanism, with Km values for l‐glutamate and DOVA of 1.92 mM and 0.48 mM respectively. Competitive parabolic substrate inhibition by DOVA at concentrations greater than 3.5–4.5 mM was observed. Glyoxylate (4–10 mM) was found to be a competitive inhibitor with respect to DOVA, whereas at low concentrations (0–4 mM) noncompetitive plots were obtained. An analysis of the possible enzyme forms involved, was carried out. In more crude preparations most of the enzyme is found to be in the form of an enzyme‐glutamate complex. Copyright © 1989, Wiley Blackwell. All rights reserved JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00142956_v182_n3_p657_LOMBARDO |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
aminolevulinate aminotransferase aminotransferase animal article darkness enzyme specificity enzyme stability enzymology Euglena gracilis growth, development and aging isolation and purification kinetics Animal Darkness Enzyme Stability Euglena gracilis Kinetics Substrate Specificity Support, Non-U.S. Gov't Transaminases |
| spellingShingle |
aminolevulinate aminotransferase aminotransferase animal article darkness enzyme specificity enzyme stability enzymology Euglena gracilis growth, development and aging isolation and purification kinetics Animal Darkness Enzyme Stability Euglena gracilis Kinetics Substrate Specificity Support, Non-U.S. Gov't Transaminases LOMBARDO, M.E. ARAUJO, L.S. JUKNAT, A.A. BATLLE, A.M.d.C. Glutamate:4,5‐dioxovaleric acid transaminase from Euglena gracilis Kinetic studies |
| topic_facet |
aminolevulinate aminotransferase aminotransferase animal article darkness enzyme specificity enzyme stability enzymology Euglena gracilis growth, development and aging isolation and purification kinetics Animal Darkness Enzyme Stability Euglena gracilis Kinetics Substrate Specificity Support, Non-U.S. Gov't Transaminases |
| description |
The kinetic properties of the enzyme l‐glutamate:4,5‐dioxovaleric acid aminotransferase (Glu: DOVA transaminase) from Euglena gracilis have been studied. 5‐Aminolevulinic acid formation was linear with time for at least 45 min at 37°C and l‐glutamate was the most effective amino‐group donor. Lineweaver‐Burk double‐reciprocal plots suggested a ping‐pong reaction mechanism, with Km values for l‐glutamate and DOVA of 1.92 mM and 0.48 mM respectively. Competitive parabolic substrate inhibition by DOVA at concentrations greater than 3.5–4.5 mM was observed. Glyoxylate (4–10 mM) was found to be a competitive inhibitor with respect to DOVA, whereas at low concentrations (0–4 mM) noncompetitive plots were obtained. An analysis of the possible enzyme forms involved, was carried out. In more crude preparations most of the enzyme is found to be in the form of an enzyme‐glutamate complex. Copyright © 1989, Wiley Blackwell. All rights reserved |
| format |
JOUR |
| author |
LOMBARDO, M.E. ARAUJO, L.S. JUKNAT, A.A. BATLLE, A.M.d.C. |
| author_facet |
LOMBARDO, M.E. ARAUJO, L.S. JUKNAT, A.A. BATLLE, A.M.d.C. |
| author_sort |
LOMBARDO, M.E. |
| title |
Glutamate:4,5‐dioxovaleric acid transaminase from Euglena gracilis Kinetic studies |
| title_short |
Glutamate:4,5‐dioxovaleric acid transaminase from Euglena gracilis Kinetic studies |
| title_full |
Glutamate:4,5‐dioxovaleric acid transaminase from Euglena gracilis Kinetic studies |
| title_fullStr |
Glutamate:4,5‐dioxovaleric acid transaminase from Euglena gracilis Kinetic studies |
| title_full_unstemmed |
Glutamate:4,5‐dioxovaleric acid transaminase from Euglena gracilis Kinetic studies |
| title_sort |
glutamate:4,5‐dioxovaleric acid transaminase from euglena gracilis kinetic studies |
| url |
http://hdl.handle.net/20.500.12110/paper_00142956_v182_n3_p657_LOMBARDO |
| work_keys_str_mv |
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1807323397558894592 |