Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.3.1 (Mg2+-ATPase)
 1,484 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have shown that red blood cell (RBC) adenosine-5'-triphosphate (ATP) is better maintained and that there is less hemolysis and K+ leakage in hypotonic experimental additive solutions (EASs) containing glutamine and glutamine plus phosphate (Pi) than in the conventional additive solution Adsol during blood bank storage. The objective of this study was to determine if the beneficial effect produced in these media correlates with better preservation of RBC membrane properties including lipid content, phospholipid organization, aminophospholipid transport (flippase), and prothrombin converting activity. Aliquots of packed RBCs were stored in EASs containing adenine, glucose, sodium chloride, and mannitol, with 10 mmol/L glutamine (EAS 44) or with 10 mmol/L glutamine and 20 mmol/L Pi(EAS 45), or in Adsol. RBC membranes were studied after 0, 28, 42, and 84 days of storage, and vesicle membranes were studied after 84 days. RBC cholesterol and phospholipid content remained significantly greater (P < .01) in EASs than in Adsol. The degree of membrane vesiculation was more than 50% lower in EASs than in Adsol (P < .01). After 42 days of storage, the accessibility of phosphatidylethanolamine to phospholipases was approximately 1.5 times greater for Adsol and EAS 44 samples than for EAS 45 samples (43.5% v 28%). The rates of phosphatidylserine transport were 43% to 70% lower for stored cells but were not dependent on storage media. The amounts of bands 3 and 4.1 in the microvesicle membranes were not statistically different in any of the preparations. These results suggest that storage of RBCs in glutamine and Pi-medium better maintains ATP, lipid content, and phospholipid asymmetry and results in decreased vesiculation.
 ...
PMID:Glutamine- and phosphate-containing hypotonic storage media better maintain erythrocyte membrane physical properties. 869 18

A cationic steroid with a hydrogen-bonding pocket that has an affinity for anionic phospholipid headgroups was synthesized and shown to strongly promote the translocation or flip-flop of a fluorescent, C(6)NBD-labeled phosphatidylserine probe (C(6)NBD-PS) across vesicle membranes. In addition, the synthetic PS scramblase increases the levels of endogenous PS on the surface of erythrocytes as monitored by flow cytometry analysis of annexin V-FITC binding. The PS scrambling effect is enhanced when the cells are pretreated with N-ethylmaleimide (NEM), an inhibitor of the endogenous aminophospholipid flippase. The combination of NEM and synthetic PS scramblase enhances the ability of erythrocytes to promote the conversion of prothrombin to thrombin by a factor of 4. An analogous cationic steroid with a smaller binding pocket has no measurable PS translocation activity, a result that is attributed to its inability to sufficiently diminish the hydrophilicity of the multiply charged PS headgroup.
 ...
PMID:Facilitated phosphatidylserine (PS) flip-flop and thrombin activation using a synthetic PS scramblase. 1283 89