Abstract
Calcium binds to membranous structures isolated from rabbit kidney cortex homogenates. The binding is enhanced by ATP and Mg++ in combination. Other nucleotides, ITP and GTP, do not have this property. In contrast to similar preparations of nerve and muscle, the binding is not augmented by oxalate (3–100 mM). Also, binding of calcium cannot be correlated with ATP hydrolysis. p-Chloromercuribenzoate and the mercurial diuretic agent mercaptomerin inhibit the binding of calcium. This system can be distinguished from the binding of calcium by mitochondria by lack of azide inhibition and by failure of ADP-succinate to substitute for ATP. 14C- and γ-32P-labeled ATP bind to the renal membranes in the absence of calcium, but only the 32P binding increases when calcium is added. The ratio of 32P bound to 45Ca bound is 2:1. The above data are consistent with a hypothesis that calcium is metabolically bound to renal membranes and that this binding is associated with membrane phosphorylation. Such a formulation may have pertinence to the conformational state of renal membranes and subsequent permeability characteristics. It also allows for the concept that membrane stability requires metabolic participation, as well as calcium ions.
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Selected References
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- Alonso G., Walser M. ATP splitting and calcium binding by brain microsomes measured with a rapid perfusion method. J Gen Physiol. 1968 Jul;52(1):111–135. doi: 10.1085/jgp.52.1.111. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carvalho A. P., Leo B. Effects of ATP on the interaction of Ca++, Mg++, and K+ with fragmented sarcoplasmic reticulum isolated from rabbit skeletal muscle. J Gen Physiol. 1967 May;50(5):1327–1352. doi: 10.1085/jgp.50.5.1327. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Lieberman E. M., Palmer R. F., Collins G. H. Calcium ion uptake by crustacean peripheral nerve subcellular particles. Exp Cell Res. 1967 May;46(2):412–418. doi: 10.1016/0014-4827(67)90077-8. [DOI] [PubMed] [Google Scholar]
- Manery J. F. Effects of Ca ions on membranes. Fed Proc. 1966 Nov-Dec;25(6):1804–1810. [PubMed] [Google Scholar]
- Martonosi A. The role of phospholipids in the ATP-ase activity of skeletal muscle microsomes. Biochem Biophys Res Commun. 1967 Dec 15;29(5):753–757. doi: 10.1016/0006-291x(67)90282-3. [DOI] [PubMed] [Google Scholar]
- Nechay B. R., Palmer R. F., Chinoy D. A., Posey V. A. The problem of Na+ + K+ adenosine triphosphatase as the receptor for diuretic action of mercurials and ethacrynic acid. J Pharmacol Exp Ther. 1967 Sep;157(3):599–617. [PubMed] [Google Scholar]
- POST R. L., SEN A. K., ROSENTHAL A. S. A PHOSPHORYLATED INTERMEDIATE IN ADENOSINE TRIPHOSPHATE-DEPENDENT SODIUM AND POTASSIUM TRANSPORT ACROSS KIDNEY MEMBRANES. J Biol Chem. 1965 Mar;240:1437–1445. [PubMed] [Google Scholar]
- ROJAS E., TOBIAS J. M. MEMBRANE MODEL: ASSOCIATION OF INORGANIC CATIONS WITH PHOSPHOLIPID MONOLAYERS. Biochim Biophys Acta. 1965 Mar 29;94:394–404. doi: 10.1016/0926-6585(65)90047-6. [DOI] [PubMed] [Google Scholar]
- Robinson J. D., Lust W. D. Adenosine triophosphate-dependent calcium accumulation by brain microsomes. Arch Biochem Biophys. 1968 Apr;125(1):286–294. doi: 10.1016/0003-9861(68)90663-2. [DOI] [PubMed] [Google Scholar]
- Sandow A. Excitation-contraction coupling in skeletal muscle. Pharmacol Rev. 1965 Sep;17(3):265–320. [PubMed] [Google Scholar]