A Kinetic Characterization of the Gill (Na+, K+)-ATPase from the Semi-terrestrial Mangrove Crab Cardisoma guanhumi Latreille, 1825 (Decapoda, Brachyura)
| العنوان: | A Kinetic Characterization of the Gill (Na+, K+)-ATPase from the Semi-terrestrial Mangrove Crab Cardisoma guanhumi Latreille, 1825 (Decapoda, Brachyura) |
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| المؤلفون: | Francisco A. Leone, Daniel L. Farias, Malson N. Lucena, Daniela P. Garçon, Fernando L. Mantelatto, John Campbell McNamara |
| المصدر: | The Journal of Membrane Biology. 250:517-534 |
| بيانات النشر: | Springer Science and Business Media LLC, 2017. |
| سنة النشر: | 2017 |
| مصطلحات موضوعية: | 030110 physiology, 0301 basic medicine, Gill, biology, Physiology, ATPase, Sodium-Potassium-Exchanging ATPase, Kinetics, Biophysics, Cell Biology, Anatomy, Mangrove crab, biology.organism_classification, Cardisoma guanhumi, Ouabain, 03 medical and health sciences, Crystallography, 030104 developmental biology, biology.protein, medicine, Na+/K+-ATPase, medicine.drug |
| الوصف: | We provide a kinetic characterization of (Na+, K+)-ATPase activity in a posterior gill microsomal fraction from the semi-terrestrial mangrove crab Cardisoma guanhumi. Sucrose density gradient centrifugation reveals two distinct membrane fractions showing considerable (Na+, K+)-ATPase activity, but also containing other microsomal ATPases. The (Na+, K+)-ATPase, notably immuno-localized to the apical region of the epithelial pillar cells, and throughout the pillar cell bodies, has an M r of around 110 kDa and hydrolyzes ATP with V M = 146.8 ± 6.3 nmol Pi min-1 mg protein-1 and K M = 0.05 ± 0.003 mmol L-1 obeying Michaelis-Menten kinetics. While stimulation by Na+ (V M = 139.4 ± 6.9 nmol Pi min-1 mg protein-1, K M = 4.50 ± 0.22 mmol L-1) also follows Michaelis-Menten kinetics, modulation of (Na+, K+)-ATPase activity by MgATP (V M = 136.8 ± 6.5 nmol Pi min-1 mg protein-1, K 0.5 = 0.27 ± 0.04 mmol L-1), K+ (V M = 140.2 ± 7.0 nmol Pi min-1 mg protein-1, K 0.5 = 0.17 ± 0.008 mmol L-1), and NH4+ (V M = 149.1 ± 7.4 nmol Pi min-1 mg protein-1, K 0.5 = 0.60 ± 0.03 mmol L-1) shows cooperative kinetics. Ouabain (K I = 52.0 ± 2.6 µmol L-1) and orthovanadate (K I = 1.0 ± 0.05 µmol L-1) inhibit total ATPase activity by around 75%. At low Mg2+ concentrations, ATP is an allosteric modulator of the enzyme. This is the first study to provide a kinetic characterization of the gill (Na+, K+)-ATPase in C. guanhumi, and will be useful in better comprehending the biochemical underpinnings of osmoregulatory ability in a semi-terrestrial mangrove crab. |
| تدمد: | 1432-1424 0022-2631 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::579f7d891ac0587365b13a0b59ece43b https://doi.org/10.1007/s00232-017-9978-6 |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi...........579f7d891ac0587365b13a0b59ece43b |
| قاعدة البيانات: | OpenAIRE |
Find this article in full text from Springer Verlag. | تدمد: | 14321424 00222631 |
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