Effect of alkaline pH on the activity and the structure of chloroplast fructose-1,6-bisphosphatase
The effect of alkaline pH on the stability of chloroplast fructose-1,6-bisphosphatase was examined. The incubation of the native enzyme (tetramer) at pH 8.9 lowered the specific activity (t0.5 = 6 min). The presence of fructose 1,6-bisphosphatase and Ca2+, two enzyme modulators, delayed the inactiva...
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1990
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01689452_v70_n1_p35_Ballicora http://hdl.handle.net/20.500.12110/paper_01689452_v70_n1_p35_Ballicora |
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paper:paper_01689452_v70_n1_p35_Ballicora2023-06-08T15:18:10Z Effect of alkaline pH on the activity and the structure of chloroplast fructose-1,6-bisphosphatase Ballicora, Miguel Angel Wolosiuk, Ricardo Alejandro chloroplasts enzyme dissociation fructose-1,6-bisphosphatase high pH The effect of alkaline pH on the stability of chloroplast fructose-1,6-bisphosphatase was examined. The incubation of the native enzyme (tetramer) at pH 8.9 lowered the specific activity (t0.5 = 6 min). The presence of fructose 1,6-bisphosphatase and Ca2+, two enzyme modulators, delayed the inactivation process (t0.5 = 50 min) whereas sodium trichloroacetate, a chaotropic anion, accelerated it (t0.5 < 1 min). On the other hand, the conversion of 60% of the enzyme to dimers required an incubation of 3 h at pH 8.9. On this basis, it appeared that an inactive tetramer form preceded the dissociation of chloroplast fructose-1,6-bisphosphatase at pH 8.9; both fructose 1,6-bisphosphate and Ca2+ prevented enzyme inactivation by stabilizing the tetramer form. These results indicated that, in addition to their roles as enzyme modulators, sugar biphosphates and bivalent cations contribute to stabilizing the active conformation of chloroplast fructose-1,6-bisphosphatase. © 1990. Fil:Ballicora, M.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Wolosiuk, R.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1990 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01689452_v70_n1_p35_Ballicora http://hdl.handle.net/20.500.12110/paper_01689452_v70_n1_p35_Ballicora |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
chloroplasts enzyme dissociation fructose-1,6-bisphosphatase high pH |
| spellingShingle |
chloroplasts enzyme dissociation fructose-1,6-bisphosphatase high pH Ballicora, Miguel Angel Wolosiuk, Ricardo Alejandro Effect of alkaline pH on the activity and the structure of chloroplast fructose-1,6-bisphosphatase |
| topic_facet |
chloroplasts enzyme dissociation fructose-1,6-bisphosphatase high pH |
| description |
The effect of alkaline pH on the stability of chloroplast fructose-1,6-bisphosphatase was examined. The incubation of the native enzyme (tetramer) at pH 8.9 lowered the specific activity (t0.5 = 6 min). The presence of fructose 1,6-bisphosphatase and Ca2+, two enzyme modulators, delayed the inactivation process (t0.5 = 50 min) whereas sodium trichloroacetate, a chaotropic anion, accelerated it (t0.5 < 1 min). On the other hand, the conversion of 60% of the enzyme to dimers required an incubation of 3 h at pH 8.9. On this basis, it appeared that an inactive tetramer form preceded the dissociation of chloroplast fructose-1,6-bisphosphatase at pH 8.9; both fructose 1,6-bisphosphate and Ca2+ prevented enzyme inactivation by stabilizing the tetramer form. These results indicated that, in addition to their roles as enzyme modulators, sugar biphosphates and bivalent cations contribute to stabilizing the active conformation of chloroplast fructose-1,6-bisphosphatase. © 1990. |
| author |
Ballicora, Miguel Angel Wolosiuk, Ricardo Alejandro |
| author_facet |
Ballicora, Miguel Angel Wolosiuk, Ricardo Alejandro |
| author_sort |
Ballicora, Miguel Angel |
| title |
Effect of alkaline pH on the activity and the structure of chloroplast fructose-1,6-bisphosphatase |
| title_short |
Effect of alkaline pH on the activity and the structure of chloroplast fructose-1,6-bisphosphatase |
| title_full |
Effect of alkaline pH on the activity and the structure of chloroplast fructose-1,6-bisphosphatase |
| title_fullStr |
Effect of alkaline pH on the activity and the structure of chloroplast fructose-1,6-bisphosphatase |
| title_full_unstemmed |
Effect of alkaline pH on the activity and the structure of chloroplast fructose-1,6-bisphosphatase |
| title_sort |
effect of alkaline ph on the activity and the structure of chloroplast fructose-1,6-bisphosphatase |
| publishDate |
1990 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_01689452_v70_n1_p35_Ballicora http://hdl.handle.net/20.500.12110/paper_01689452_v70_n1_p35_Ballicora |
| work_keys_str_mv |
AT ballicoramiguelangel effectofalkalinephontheactivityandthestructureofchloroplastfructose16bisphosphatase AT wolosiukricardoalejandro effectofalkalinephontheactivityandthestructureofchloroplastfructose16bisphosphatase |
| _version_ |
1768541747380486144 |