Cation-activated phosphatase activities in islet cell plasma membrane preparations.
(1980) In Hormone and Metabolic Research, Supplement Suppl 10. p.55-61- Abstract
Pancreatic islets from rats or ob/ob mice were homogenized and fractionated either by a two-step or one-step sucrose gradient centrifugation. A plasma membrane enriched fraction was obtained at a sucrose density of about 1.10. The distribution of the plasma membrane probe 125I-wheat germ agglutinin was parallel to that of other plasma membrane markers. Hydrolysis of Mg-ATP-gamma-3Pp in rat islet membranes was of high specific activity, but was little affected by K+ and/or Na+. K+-activated, ouabain-sensitive phosphatase activities were, on the other hand, readily demonstrated in both rat and ob/ob mouse islet membranes. The K+-activated hydrolysis of organophosphate indicators were markedly inhibited by ATP. The binding of 45Ca2+ to... (More)
Pancreatic islets from rats or ob/ob mice were homogenized and fractionated either by a two-step or one-step sucrose gradient centrifugation. A plasma membrane enriched fraction was obtained at a sucrose density of about 1.10. The distribution of the plasma membrane probe 125I-wheat germ agglutinin was parallel to that of other plasma membrane markers. Hydrolysis of Mg-ATP-gamma-3Pp in rat islet membranes was of high specific activity, but was little affected by K+ and/or Na+. K+-activated, ouabain-sensitive phosphatase activities were, on the other hand, readily demonstrated in both rat and ob/ob mouse islet membranes. The K+-activated hydrolysis of organophosphate indicators were markedly inhibited by ATP. The binding of 45Ca2+ to mouse islet plasma membranes was increased by ATP. Cation transport and the interaction of Ca2+ with the islet cell plasma membrane may be dependent on phosphoryl-transfer reactions with ATP as the physiological substrate.
(Less)
- author
- Lernmark, A. LU ; Nielsen, D. A. ; Parman, A. U. ; Sehlin, J. ; Steiner, D. F. and Täljedal, I. B.
- publishing date
- 1980-12-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Hormone and Metabolic Research, Supplement
- volume
- Suppl 10
- pages
- 7 pages
- publisher
- Georg Thieme Verlag
- external identifiers
-
- scopus:0019268120
- pmid:6256271
- ISSN
- 0170-5903
- language
- English
- LU publication?
- no
- id
- 2a59f427-3e43-484e-9ba3-bade9cabdae3
- date added to LUP
- 2019-09-16 15:37:21
- date last changed
- 2024-03-13 08:13:02
@article{2a59f427-3e43-484e-9ba3-bade9cabdae3, abstract = {{<p>Pancreatic islets from rats or ob/ob mice were homogenized and fractionated either by a two-step or one-step sucrose gradient centrifugation. A plasma membrane enriched fraction was obtained at a sucrose density of about 1.10. The distribution of the plasma membrane probe 125I-wheat germ agglutinin was parallel to that of other plasma membrane markers. Hydrolysis of Mg-ATP-gamma-3Pp in rat islet membranes was of high specific activity, but was little affected by K+ and/or Na+. K+-activated, ouabain-sensitive phosphatase activities were, on the other hand, readily demonstrated in both rat and ob/ob mouse islet membranes. The K+-activated hydrolysis of organophosphate indicators were markedly inhibited by ATP. The binding of 45Ca2+ to mouse islet plasma membranes was increased by ATP. Cation transport and the interaction of Ca2+ with the islet cell plasma membrane may be dependent on phosphoryl-transfer reactions with ATP as the physiological substrate.</p>}}, author = {{Lernmark, A. and Nielsen, D. A. and Parman, A. U. and Sehlin, J. and Steiner, D. F. and Täljedal, I. B.}}, issn = {{0170-5903}}, language = {{eng}}, month = {{12}}, pages = {{55--61}}, publisher = {{Georg Thieme Verlag}}, series = {{Hormone and Metabolic Research, Supplement}}, title = {{Cation-activated phosphatase activities in islet cell plasma membrane preparations.}}, volume = {{Suppl 10}}, year = {{1980}}, }