Related Articles7Li NMR relaxation study of Li+ binding in human erythrocytes.
Biochemistry. 1993 Dec 14;32(49):13490-8
Authors: Rong Q, Espanol M, Mota de Freitas D, Geraldes CF
We used 7Li NMR spin-lattice (T1) and spin-spin (T2) relaxation time measurements to investigate the binding of Li+ in human red blood cell (RBC) suspensions. In RBCs containing 1.4 mM Li+, the intracellular 7Li NMR T2 relaxation value (0.30 +/- 0.03 s) was much smaller than the corresponding T1 value (6.0 +/- 0.1 s), yielding a ratio of T1 to T2 of 20. For 1.5 mM LiCl solutions whose viscosities were adjusted to 5 cP with glycerol, the values of the T1/T2 ratios were as follows: 49 for unsealed RBC membrane (2.0 mg of protein/mL); 4.4 for spectrin (1.9 mg/mL); 1.5 for 5.4 mM 2,3-bisphosphoglycerate (BPG); 2.2 for 2.7 mM carbonmonoxyhemoglobin (COHb); 1.6 for 2.0 mM ATP; and 1.2 for a 50/50% (v/v) glycerol-water mixture. Intracellular viscosity and the electric field gradients experienced by Li+ when traversing the spectrin-actin network therefore are not responsible for the large values of the T1/T2 ratios observed in Li(+)-loaded RBCs. We conclude that the RBC membrane is the major Li+ binding site in Li(+)-loaded RBCs (Kb = 215 +/- 36 M-1) and that the binding of Li+ to COHb, BPG, spectrin-actin, or ATP is weak. Partially relaxed 7Li NMR spectra of Li(+)-containing RBC membrane suspensions indicated the presence of two relaxation components, one broad and one narrow.(ABSTRACT TRUNCATED AT 250 WORDS)
Role of aminotransferases in glutamate metabolism of human erythrocytes
Role of aminotransferases in glutamate metabolism of human erythrocytes
Abstract Human erythrocytes require a continual supply of glutamate to support glutathione synthesis, but are unable to transport this amino acid across their cell membrane. Consequently, erythrocytes rely on de novo glutamate biosynthesis from α-ketoglutarate and glutamine to maintain intracellular levels of glutamate. Erythrocytic glutamate biosynthesis is catalyzed by three enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and glutamine aminohydrolase (GA). Although the presence of these...
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[NMR paper] Identification of Li(+) binding sites and the effect of Li(+) treatment on phospholipid composition in human neuroblastoma cells: a (7)Li and (31)P NMR study.
Identification of Li(+) binding sites and the effect of Li(+) treatment on phospholipid composition in human neuroblastoma cells: a (7)Li and (31)P NMR study.
Related Articles Identification of Li(+) binding sites and the effect of Li(+) treatment on phospholipid composition in human neuroblastoma cells: a (7)Li and (31)P NMR study.
Biochim Biophys Acta. 2005 Sep 25;1741(3):339-49
Authors: Layden BT, Abukhdeir AM, Malarkey C, Oriti LA, Salah W, Stigler C, Geraldes CF, Mota de Freitas D
Li(+) binding in subcellular fractions of human...
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[NMR paper] NMR study of the binding of all-trans-retinoic acid to type II human cellular retinoi
NMR study of the binding of all-trans-retinoic acid to type II human cellular retinoic acid binding protein.
Related Articles NMR study of the binding of all-trans-retinoic acid to type II human cellular retinoic acid binding protein.
Biochim Biophys Acta. 1999 Aug 17;1433(1-2):240-52
Authors: Wang L, Yan H
Cellular RA binding proteins are thought to play important roles in the (RA), a hormonally active metabolite of vitamin A that has profound effects on cell growth, + differentiation and morphogenesis. Binding of RA to type II human cellular...
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[NMR paper] The substrate binding site of human liver cytochrome P450 2C9: an NMR study.
The substrate binding site of human liver cytochrome P450 2C9: an NMR study.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--pubs.acs.org-images-acspubs.jpg Related Articles The substrate binding site of human liver cytochrome P450 2C9: an NMR study.
Biochemistry. 1997 Oct 21;36(42):12672-82
Authors: Poli-Scaife S, Attias R, Dansette PM, Mansuy D
Purified recombinant human liver cytochrome P450 2C9 was produced, from expression of the corresponding cDNA in yeast, in quantities large enough for UV-visible and 1H NMR experiments. Its...
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[NMR paper] 13C-NMR relaxation study on mobility of the DNA-binding arm of HU.
13C-NMR relaxation study on mobility of the DNA-binding arm of HU.
Related Articles 13C-NMR relaxation study on mobility of the DNA-binding arm of HU.
J Biochem. 1994 Nov;116(5):1153-5
Authors: Kakuta Y, Hojo H, Aimoto S, Tanaka I, Hikichi K
The mobility of the DNA-binding arm of HU protein was studied by 13C-NMR spectroscopy. The correlation times tau c of Phe47C alpha in the body and Gly60C alpha in the arm of HU were determined for HU and HU-DNA complex. The value of tau c of Phe47C alpha is 2-4 times larger than that of Gly60C alpha...
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[NMR paper] Relaxation study of the backbone dynamics of human profilin by two-dimensional 1H-15N
Relaxation study of the backbone dynamics of human profilin by two-dimensional 1H-15N NMR.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-PubMedLink.gif Related Articles Relaxation study of the backbone dynamics of human profilin by two-dimensional 1H-15N NMR.
FEBS Lett. 1993 Dec 28;336(3):457-61
Authors: Constantine KL, Friedrichs MS, Bell AJ, Lavoie TB, Mueller L, Metzler WJ
The dynamic properties of 111 backbone HN sites in uncomplexed human profilin, a protein of 139 residues, have been...
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[NMR paper] Study on the erythrocytes from myotonic dystrophy with multi-nuclear NMR.
Study on the erythrocytes from myotonic dystrophy with multi-nuclear NMR.
Related Articles Study on the erythrocytes from myotonic dystrophy with multi-nuclear NMR.
Muscle Nerve. 1991 Jan;14(1):57-63
Authors: Kuwabara T, Yuasa T, Ohno T, Yamamuro M, Miyatake T
We have studied the water permeability through membranes, the function of the Na pump, and glucose metabolism of erythrocytes of patients with myotonic muscular dystrophy (MyD) using 1H--, 23Na, and 13C-NMR techniques. A significant decrease in water permeability was recognized in the...
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[NMR paper] Hypophosphite transport in human erythrocytes studied by overdetermined one-dimension
Hypophosphite transport in human erythrocytes studied by overdetermined one-dimensional NMR exchange analysis.
Related Articles Hypophosphite transport in human erythrocytes studied by overdetermined one-dimensional NMR exchange analysis.
NMR Biomed. 1990 Apr;3(2):59-63
Authors: Price WS, Kuchel PW
The membrane transport kinetics of the disubstituted phosphorus oxyacid, hypophosphite, were studied in human red cells under equilibrium exchange conditions. Hypophosphite is an analogue of both the bicarbonate and phosphate ions and is known to be...