Biochemical characterization of the hippocampal and striatal Na,K-ATPase reveals striking differences in kinetic properties
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1997
Authors
Peković, SanjaNedeljković, N.
Nikezić, Gordana S.
Horvat, Anica
Stojiljković, Mirjana
Rakić, Ljubisav
Martinović, Jelena
Article (Published version)
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The activities and basic enzymatic properties of Na,K-ATPase were examined in synaptosomal plasma membranes (SPM) prepared from rat hippocampus and striatum. A kinetic analysis showed profound differences in apparent affinities for ATP (K-m) between hippocampal (1.21 mmol/l) and striatal (0.76 mmol/l) enzyme preparations, as well as in the corresponding V-max values. However, physiological efficiencies were almost the same. The complex pattern of dose-response curves to ouabain indicated the presence of two high-affinity forms of Na,K-ATPase in the striatum (very high-:K-i = 3.73 x 10(-8) mol/l and high-:K-i = 4.21 x 10(-5) mol/l), and one high affinity form in the hippocampus (K-i = 6.6 x 10(-7) mol/l). In addition, both SPM preparations contained one low affinity form with similar K-i. The very high-affinity form had positive cooperativity for ouabain inhibition of Na,K-ATPase activity, in contrast to high- and low-affinity forms, which exhibited negative cooperativity. The respectiv...e contributions of ouabain-sensitive forms to the total activity were estimated as 22%, 46%, 19% for the striatum and 36%, 45% for the hippocampus. These data clearly demonstrate striking differences in kinetic properties of the hippocampal and striatal Na,K-ATPase that may be due to the isoenzyme diversity and adaptation to specific physiological demands of the examined rat brain regions.
Keywords:
Na,K-ATPase / synaptic plasma membranes / hippocampus / striatum / ratSource:
General Physiology and Biophysics, 1997, 16, 3, 227-240Collections
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VinčaTY - JOUR AU - Peković, Sanja AU - Nedeljković, N. AU - Nikezić, Gordana S. AU - Horvat, Anica AU - Stojiljković, Mirjana AU - Rakić, Ljubisav AU - Martinović, Jelena PY - 1997 UR - https://vinar.vin.bg.ac.rs/handle/123456789/2098 AB - The activities and basic enzymatic properties of Na,K-ATPase were examined in synaptosomal plasma membranes (SPM) prepared from rat hippocampus and striatum. A kinetic analysis showed profound differences in apparent affinities for ATP (K-m) between hippocampal (1.21 mmol/l) and striatal (0.76 mmol/l) enzyme preparations, as well as in the corresponding V-max values. However, physiological efficiencies were almost the same. The complex pattern of dose-response curves to ouabain indicated the presence of two high-affinity forms of Na,K-ATPase in the striatum (very high-:K-i = 3.73 x 10(-8) mol/l and high-:K-i = 4.21 x 10(-5) mol/l), and one high affinity form in the hippocampus (K-i = 6.6 x 10(-7) mol/l). In addition, both SPM preparations contained one low affinity form with similar K-i. The very high-affinity form had positive cooperativity for ouabain inhibition of Na,K-ATPase activity, in contrast to high- and low-affinity forms, which exhibited negative cooperativity. The respective contributions of ouabain-sensitive forms to the total activity were estimated as 22%, 46%, 19% for the striatum and 36%, 45% for the hippocampus. These data clearly demonstrate striking differences in kinetic properties of the hippocampal and striatal Na,K-ATPase that may be due to the isoenzyme diversity and adaptation to specific physiological demands of the examined rat brain regions. T2 - General Physiology and Biophysics T1 - Biochemical characterization of the hippocampal and striatal Na,K-ATPase reveals striking differences in kinetic properties VL - 16 IS - 3 SP - 227 EP - 240 UR - https://hdl.handle.net/21.15107/rcub_vinar_2098 ER -
@article{ author = "Peković, Sanja and Nedeljković, N. and Nikezić, Gordana S. and Horvat, Anica and Stojiljković, Mirjana and Rakić, Ljubisav and Martinović, Jelena", year = "1997", abstract = "The activities and basic enzymatic properties of Na,K-ATPase were examined in synaptosomal plasma membranes (SPM) prepared from rat hippocampus and striatum. A kinetic analysis showed profound differences in apparent affinities for ATP (K-m) between hippocampal (1.21 mmol/l) and striatal (0.76 mmol/l) enzyme preparations, as well as in the corresponding V-max values. However, physiological efficiencies were almost the same. The complex pattern of dose-response curves to ouabain indicated the presence of two high-affinity forms of Na,K-ATPase in the striatum (very high-:K-i = 3.73 x 10(-8) mol/l and high-:K-i = 4.21 x 10(-5) mol/l), and one high affinity form in the hippocampus (K-i = 6.6 x 10(-7) mol/l). In addition, both SPM preparations contained one low affinity form with similar K-i. The very high-affinity form had positive cooperativity for ouabain inhibition of Na,K-ATPase activity, in contrast to high- and low-affinity forms, which exhibited negative cooperativity. The respective contributions of ouabain-sensitive forms to the total activity were estimated as 22%, 46%, 19% for the striatum and 36%, 45% for the hippocampus. These data clearly demonstrate striking differences in kinetic properties of the hippocampal and striatal Na,K-ATPase that may be due to the isoenzyme diversity and adaptation to specific physiological demands of the examined rat brain regions.", journal = "General Physiology and Biophysics", title = "Biochemical characterization of the hippocampal and striatal Na,K-ATPase reveals striking differences in kinetic properties", volume = "16", number = "3", pages = "227-240", url = "https://hdl.handle.net/21.15107/rcub_vinar_2098" }
Peković, S., Nedeljković, N., Nikezić, G. S., Horvat, A., Stojiljković, M., Rakić, L.,& Martinović, J.. (1997). Biochemical characterization of the hippocampal and striatal Na,K-ATPase reveals striking differences in kinetic properties. in General Physiology and Biophysics, 16(3), 227-240. https://hdl.handle.net/21.15107/rcub_vinar_2098
Peković S, Nedeljković N, Nikezić GS, Horvat A, Stojiljković M, Rakić L, Martinović J. Biochemical characterization of the hippocampal and striatal Na,K-ATPase reveals striking differences in kinetic properties. in General Physiology and Biophysics. 1997;16(3):227-240. https://hdl.handle.net/21.15107/rcub_vinar_2098 .
Peković, Sanja, Nedeljković, N., Nikezić, Gordana S., Horvat, Anica, Stojiljković, Mirjana, Rakić, Ljubisav, Martinović, Jelena, "Biochemical characterization of the hippocampal and striatal Na,K-ATPase reveals striking differences in kinetic properties" in General Physiology and Biophysics, 16, no. 3 (1997):227-240, https://hdl.handle.net/21.15107/rcub_vinar_2098 .