Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Measurements have been made of the flexibility and respiratory efficiency of erythrocytes stored in acid-citrate-dextrose (ACD).2. The rate of packing of stored blood, during centrifugation, indicates that the red blood cells are relatively inflexible.3. Spectrophotometric observations, using the rapid-mixing and stopped-flow technique, indicate that the rate of egress of oxygen from HbO(2) in these erythrocytes is significantly reduced. This is not due to a change of the chemical rate of dissociation of HbO(2).4. Neither factor is significantly reversed by resuspending the cells in Ringer-Locke solution or adjusting to pH 7.4.5. A small improvement is obtained by adding hypertonic NaCl or incubating the blood at 37 degrees C for 1 hr.6. Incubation with adenosine, 25 mu-mole/ml. blood, at 37 degrees C for at least 1 hr, restored both the respiratory function and flexibility to normal.
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PMID:The respiratory efficiency and flexibility of erythrocytes stored in acid-citrate-dextrose solution. 582 31

1. The cell-wall composition of Aspergillus niger has been investigated. Analysis shows the presence of six sugars, glucose, galactose, mannose, arabinose, glucosamine and galactosamine, all in the d-configuration, except that a small amount of l-galactose may be present. Sixteen common amino acids are also present. 2. The wall consists chiefly of neutral carbohydrate (73-83%) and hexosamine (9-13%), with smaller amounts of lipid (2-7%), protein (0.5-2.5%) and phosphorus (less than 0.1%). The acetyl content (3.0-3.4%) corresponds to 1.0mole/mole of hexosamine nitrogen. 3. A fractionation of the cell-wall complex was achieved, with or without a preliminary phenol extraction, by using n-sodium hydroxide. Though this caused some degradation, 30-60% of the wall could be solubilized (depending on the preparation). Analyses on several fractions suggest that fractionation procedures bring about some separation of components although not in a clear-cut fashion. 4. Cell-wall preparations were shown to yield a fraction having [alpha](D) approx. +240 degrees (in n-sodium hydroxide) and consisting largely of glucose. This was separated into two subfractions, one of which had [alpha](D)+281 degrees (in n-sodium hydroxide) and had properties resembling the polysaccharide nigeran; the other had [alpha](D) +231 degrees (in n-sodium hydroxide). It is suggested that nigeran is a cell-wall component.
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PMID:The composition of the cell wall of Aspergillus niger. 586 4

1. The lipopolysaccharides of a representative selection of Shigella flexneri serotypes all contain the same constituents as Salmonella chemotype VII, namely, aldoheptose phosphate, 3-deoxy-2-oxo-octonate, O-phosphorylethanolamine, d-galactose, d-glucose, N-acetyl-d-glucosamine and l-rhamnose. 2. The presence of all the Salmonella basal sugars in Sh. flexneri lipopolysaccharides is consistent with the view that the latter contain a basal structure or core which is similar to the common basal structure of Salmonella lipopolysaccharides. 3. Although the Sh. flexneri lipopolysaccharides belong to one chemotype, there appear to be quantitative differences in the composition of their O-specific side chains. The repeating units of Sh. flexneri serotypes 1a, 2a, 3a, 4a, and variant X contain d-glucose, N-acetyl-d-glucosamine and l-rhamnose in the proportions 1:1:2 respectively. The analogous repeating units of serotypes 5a and 6 contain an additional mole of d-glucose and d-galactose respectively and that of variant Y 1 mole of d-glucose less.
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PMID:The immunochemistry of Shigella flexneri lipopolysaccharides. A quantitative analysis of their monosaccharide constituents. 591 35

The vesicular stomatitis virus glycoprotein reconstituted into dipalmitoylphosphatidylcholine (DPPC) vesicles exerts a profound effect upon the DPPC gel to liquid-crystalline phase transition. The glycoprotein was reconstituted into DPPC vesicles by octyl glucoside dialysis. The gel to liquid-crystalline phase transition of these vesicles was monitored by differential scanning calorimetry. Vesicles formed in the absence of glycoprotein (600--2100-A diameter) underwent the phase transition at 41.0 degrees C and had an associated enthalpy change of 8.0 +/- 1.6 kcal/mol. Increasing the mole ratio of glycoprotein to DPPC in the vesicles to 0.15 mol % reduced both the transition temperature and the transition enthalpy change. The enthalpy change as a function of the mole percent glycoprotein could be fit to a straight line by a least-squares procedure. Extrapolation of the results to the glycoprotein concentration where the enthalpy change was zero indicated one glycoprotein molecule bound 270 +/- 150 molecules of DPPC.
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PMID:Thermotropic behavior of dipalmitoylphosphatidylcholine vesicles reconstituted with the glycoprotein of vesicular stomatitis virus. 624 46

An acid protease from the rat Murphy-Sturm lymphosarcoma (MSLS) tumor was purified 640-fold by extraction of the tumor tissue, acid precipitation with glacial acetic acid, ammonium sulfate precipitation, DEAE-Sephadex A-50 batch adsorption, QAE-Sephadex A-50 column chromatography, Sephadex G-200 gel filtration, and CM-32 cellulose chromatography. The protease hydrolyzed bovine hemoglobin and formed vasopeptide kinins when incubated with purified rat plasma kininogen. Two protease fractions obtained by Sephadex G-200 gel filtration had identical molecular weights of 39,500-41,000 and were similar in other physico-chemical and kinetic characteristics. The purified enzyme showed three major isozymic forms (alpha, beta and gamma) with isoelectric points (pI) of 5.2, 5.5 and 5.8, respectively, and nearly identical amino acid compositions. The enzyme had a high moles percent of both aspartic and glutamic acids. The carbohydrate moiety of the enzyme contained 2 moles of N-acetylglucosamine and 8 moles of mannose per mole of enzyme. The pH optimum for the digestion of bovine hemoglobin was approximately 3.0 with a sharp decline of activity on either side of the pH optimum. The protease activity was very stable above pH 3.4. The Km values for the purified enzyme fractions A and B were 31.17 and 31.19 microM, respectively, and the corresponding Vmax values were 6.17 and 5.5 microM tyrosine per mg per min at 37 degrees and pH 3.0. The enzyme was inhibited strongly by pepstatin (Ki = 31 X 10(-9)M and alpha = 0.1). The acid protease released kinin from purified rat plasma kininogen at an initial rapid rate which plateaued at 460 ng bradykinin equivalents/mg substrate after a 2-hr incubation at 37 degrees.
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PMID:Rodent kinin-forming enzyme systems--II. Purification and characterization of an acid protease from Murphy-Sturm lymphosarcoma. 640 12

The possible role of Ca2+ as an essential constituent part of the human factor VIII complex has been investigated by stability studies, metal determinations, and gel filtration experiments. In citrated plasma, the factor VIII coagulant activity (VIII:C) deteriorated during storage in a biphasic manner. Collection of blood in heparin, instead of chelating anticoagulants, or neutralization of citrate by addition of CaCl2 to heparinized citrate phosphate dextrose (CPD) plasma rendered VIII:C noticeably stable. At physiologic levels of ionized calcium, VIII:C was almost completely stable during incubation of plasma for 6 hr at 37 degrees C. The influence of other divalent ions was also studied. Highly purified factor VIII complex was subjected to atomic absorption spectrophotometric analysis and found to contain about 1.0 mole calcium per 220,000 daltons. This intrinsic calcium could be readily removed by EDTA. When heparin plasma and CPD plasma were chromatographed on Sepharose CL-6B at 37 degrees C, all the factor-VIII-related activities eluted together as large protein complexes. In contrast, factor VIII coagulant antigen (VIII:CAg) and factor-VIII-related antigen (VIIIR:Ag) were completely dissociated upon exposure to EDTA. From these observations it is concluded that human factor VIII circulates in normal plasma as a calcium-linked protein complex.
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PMID:Human factor VIII: a calcium-linked protein complex. 641 52

In cultured melanotic melanoma, a marked decrease of pigmentation has been found to be induced by the addition of tunicamycin [Y. Mishima and G. Imokawa (1983) J. Invest. Dermatol. 81, 106-114]. Since it appears that this impaired pigmentation arises from the loss of asparagine-linked sugar chains serving as a signal for transport of tyrosinase from GERL (Golgi-associated endoplasmic reticulum of lysosomes) to premelanosomes, tyrosinases from the membrane fraction of Greene's hamster melanoma have been purified, and the structures of their sugar chains have been analyzed. Two kinds of tyrosinases were purified by Triton X-100 solubilization; DEAE-cellulose, Sephadex G-200, and DEAE-Sephadex column chromatography; and preparative polyacrylamide gel electrophoresis. The two tyrosinases were separated by polyacrylamide gel electrophoresis, and both corresponded to Mr 69,000. Their asparagine-linked sugar chains were released by hydrazinolysis and analyzed. The sugar chains of the two tyrosinases were identical except for the sialic acid contents. One mole of each tyrosinase contained 1 mol of high-mannose-type sugar chains and 3 mol of complex-type sugar chains. The former chain has Man3 approximately 5 X GlcNAc2 and the latter has Man3 X GlcNAc beta 1----4(+/- Fuc alpha 1----6)GlcNAc as their core structures. The complex-type sugar chains are composed of mono-, bi-, tri-, and tetraantennary sugar chains, with +/- Sia alpha 2----3Gal beta 1----4GlcNAc beta 1----as their outer chains.
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PMID:Purification of hamster melanoma tyrosinases and structural studies of their asparagine-linked sugar chains. 643 39

Homozygous horse transferrin (Tf O) is highly heterogeneous. In starch gel electrophoresis it gives at least 9 zones. Two main components (2a and 4b) were purified by rivanol and ammonium sulphate precipitation, DEAE-Sephadex chromatography and SP-Sephadex chromatography. Molecular weights of 75 200 and 80 500 for components 2a and 4b, respectively, were determined by sedimentation equilibrium ultracentrifugation. Amino acid compositions of the two components were similar, and there were no differences in the N-terminus (glutamic acid followed by glutamine) and the C-terminus (valine). Differences were found in carbohydrate composition between components 2a and 4b. Component 2a contained 10 moles of sugar components per mole of protein (4 hexoses, 4 hexosamines and 2 sialic acids), while component 4b contained twice the number of both total carbohydrates and individual sugar components. Carbohydrates were identified as mannose and galactose (ratio mannose: galactose approximately equal to 1.5:1), N-acetylglucosamine and N-acetylneuraminic acid. At present it is not clear whether the difference between the two components resides solely in the difference of carbohydrate contents. It is proposed that component 2a has one diantennary glycan, while component 4b has two.
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PMID:Heterogeneity of horse transferrin: the role of carbohydrate moiety. 649 65

The static head method for determining the charge stoichiometry (the number of moles of charge translocated per mole of substrate) of a coupled transport system is presented. The method involves establishing experimental conditions under which a membrane potential exactly balances the thermodynamic driving force of a known substrate gradient. The charge stoichiometry can then be calculated from thermodynamic principles. In contrast to the usual steady-state method for determining charge stoichiometry in cell suspensions and vesicle preparations, the static head method is applicable to systems which are not capable of maintaining a constant membrane potential over time. The charge stoichiometries of two renal sodium coupled D-glucose transporters previously identified in brush-border membrane vesicle preparations from the outer cortex (early proximal tubule) and outer medulla (late proximal tubule) are determined. The charge stoichiometries of these transporters are in good agreement with their sodium/glucose coupling ratios arguing against the possibility that glucose transport is coupled to ions other than sodium in these membranes.
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PMID:The static head method for determining the charge stoichiometry of coupled transport systems. Applications to the sodium-coupled D-glucose transporters of the renal proximal tubule. 653 96

Conscious rats received infusions at 5.8 ml./hr of either 0.9% NaCl or 5% dextrose, via a tail vein, for 6 hr. During this infusion period, urine was collected from the animals, and the urine volume, sodium concentration and immunoreactive PGE2 were determined. Urine flow in both groups was stable during the 2-6 hr period of the infusion and was not significantly different between the two groups. Sodium output was also stable over the 2-6 hr infusion period but obviously the output of the saline-infused group was higher than that of the dextrose-infused group. Urinary PGE2 output was not significantly different between the groups in the 2-4 hr period (79.4 +/- 8.6 p-mole/2 hr in the saline-infused group, 82.1 +/- 5.7 p-mole/2 hr in the dextrose-infused group). In the 4-6 hr period, PGE2 output remained at this level (82.0 +/- 7.8 p-mole/2 hr) in the dextrose-infused group, but fell significantly (to 53.7 +/- 5.0 p-mole/2 hr) in the saline-infused group. In separate groups of animals which received saline or dextrose infusions as above, renal papillary osmolality was determined. The osmolality was significantly (P less than 0.001) higher in the saline-infused group. It is concluded that renal PGE2 synthesis is unlikely to be directly involved in sodium homeostasis and that PGE2 synthesis as measured by urinary PGE2 excretion is not controlled by the papillary osmolality.
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PMID:Prostaglandin E2 excretion, urine flow and papillary osmolality during saline or dextrose infusion in the conscious rat. 657 30


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