Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.2.13 (aldolase)
 3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The binding isotherms of native bovine serum albumin with cationic detergents, such as octyl, decyl, dodecyl and tetradecylpyridinium bromides were determined at pH 6.8 and 3.4 at 25 degrees C. The isotherms for dodecyl and tetradecylpyridinium bromides were also determined at 3 degrees C. The average number of detergent cations bound increased with increasing hydrocarbon chain length. At low detergent concentration the binding of all alkylpyridinium bromides was smaller at pH 3.4 than at pH 6.8. Dodecylpyridinium bromide was bound to native beta-lactoglobulin, aldolase, ovalbumin, haemoglobin, myoglobin, lysozyme, trypsin and ribonuclease at pH 6.8. No binding occurred to alpha-chymotrypsin and chymotrypsinogen. The free enthalpy change, --delta G degrees, calculated from intrinsic association constants K was determined.
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PMID:Protein-cationic detergent interaction. Equilibrium dialysis study of the interaction of bovine serum albumin and other proteins with alkylpyridinium bromide. 49 43

We have developed a method for the simultaneous purification of hexokinase, glucosephosphate isomerase, phosphofructokinase, fructose-1,6-bisphosphate aldolase, triosephosphate isomerase, D-glyceraldehyde-phosphate dehydrogenase, phosphoglycerate kinase, glycerol-3-phosphate dehydrogenase and glycerol kinase from Trypanosoma brucei in yields varying over 8-55%. Crude glycosomes were prepared by differential centrifugation of cell homogenates. Subsequent hydrophobic interaction chromatography on phenyl-Sepharose resulted in six pools containing various mixtures of enzymes. These pools were processed via affinity chromatography (immobilized ATP), hydrophobic interaction chromatography (octyl-Sepharose) and ion-exchange chromatography (CM- and DEAE-cellulose) which resulted in the purification of all nine enzymes. The native enzyme and subunit molecular masses, as determined by gel filtration and gel electrophoresis under denaturing conditions, were compared with those of their homologous counterparts from other organisms. Trypanosomal hexokinase is a hexamer and differs in subunit composition from the mammalian enzymes (monomers) as well as in subunit size (51 kDa versus 96-100 kDa, respectively). Phosphofructokinase only differs in subunit size (51 kDa for T. brucei versus 80-90 kDa for mammals) but had identical subunit composition (tetrameric). The others all have the same subunit composition as their mammalian counterparts. Except for triosephosphate isomerase, all Trypanosoma enzymes have subunits which are 1-5 kDa larger in size. Together these nine enzymes contribute 3.3 +/- 1.6% to the total cellular protein of T. brucei and at least 90% to the total glycosomal protein. A comparison of calculated intraglycosomal concentrations of the enzymes with the glycosomal metabolite concentrations shows that in the case of aldolase, glyceraldehyde-phosphate dehydrogenase and phosphoglycerate kinase, the concentration of active sites is of the same order of magnitude as that of their reactants. A common feature of the glycosomal glycolytic enzymes (with the exception of glucosephosphate isomerase) is that they are highly basic proteins with pI values between 8.8 and 10.2, values which are 1-4 higher than in the case of their mammalian cytosolic counterparts and 3-6 higher than in the case of the various unicellular organisms. It is suggested that both the larger subunit size and the basic character of the T. brucei glycolytic proteins are involved in the routing of the enzymes from their site of biogenesis (the cytosol) towards their site of action (the glycosome).
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PMID:Glycolytic enzymes of Trypanosoma brucei. Simultaneous purification, intraglycosomal concentrations and physical properties. 294 90

Recent studies in our laboratory have been aimed at biochemically characterizing the alpha 2M receptor present on fibroblast membranes. The approach we have taken is to develop a means of assessing binding to solubilized alpha 2M binding sites. The binding activity was not removed by treatment with high salt concentration or treatment with chaotropic agents. Removal of the binding activity from membranes did occur using a variety of detergents which suggests that the receptor molecules may be "intrinsic" membrane proteins. The most useful detergent for solubilizing the alpha 2M receptor was octyl-beta-D-glucoside. The alpha 2M binding activity could be removed from NRK fibroblasts and Vero cells using this detergent and was found to remain in solution at 100,000 X g. Removal of the octyl-beta-D-glucoside by extensive dialysis resulted in formation of protein-lipid aggregates that bind to 125I-alpha 2M specifically and with high affinity. Such binding sites were not generated when KB cells (which lack receptors) were extracted with the detergent. Significantly, the observed affinities detected for both high- and low-affinity binding sites were similar to those reported with intact cells or membranes. In addition, binding to the solubilized sites could be inhibited using compounds known to block the receptor-mediated endocytosis of alpha 2M (bacitracin, IBHNA). Other compounds (monensin, dansylcadaverine), which did not directly inhibit the high-affinity binding sites, may exert their effects at different stages in receptor-mediated endocytosis (i.e., receptor recycling). alpha 2M binding sites from NIH-3T3 (spontaneous) tumors have been purified approximately 95-fold by a combination of ion exchange and gel permeation chromatography. The receptor appears to be an acidic protein that approximately coelutes with aldolase (45 A, 158,000 daltons) on gel filtration. Ion exchange chromatography appears to remove an endogenous inhibitor of alpha 2M binding and may also remove binding sites having lower affinity for 125I-alpha 2M. Recent studies using immobilized alpha 2M as an affinity resin suggest that the high-affinity alpha 2M receptor may have a subunit molecular weight of approximately 85,000. Studies are now in progress aimed at further characterizing these high-affinity binding sites. Once bound to the alpha 2M receptor, alpha 2M enters cells via coated pits and is rapidly transferred to receptosomes. These organelles carry the ligand into the Golgi region, from which it is transferred to lysosomes where it is slowly degraded.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Receptor-mediated endocytosis of alpha 2-macroglobulin: solubilization and partial purification of the fibroblast alpha 2-macroglobulin receptor. 620 15

A tungsten-binding protein was purified from a plasma membrane preparation of the iron-oxidizing bacterium, Acidithiobacillus ferrooxidans AP19-3 in an electrophoretically homogenous state. The protein was composed of two subunits with apparent molecular masses of 12 and 20.7 kDa. The molecular mass of the native protein was estimated to be 26.4 kDa in the presence of 1.5% 1-o-octyl-D -glucopyranoside (OGL), indicating that the native tungsten-binding protein is a heterodimeric protein. The amounts of tungsten bound to 1 mg of plasma membranes of A. ferrooxidans AP19-3 and the purified tungsten-binding protein at pH 3.0 were 191 and 1506 mug, respectively. In contrast, the amounts of tungsten bound to 1 mg of albumin, aldolase, catalase, chymotrypsinogen A, ferritin, and ferredoxin at pH 3.0 were 13.1, 18.6, 12.8, 16.6, 11.4, and 6.1 mug, respectively. Incubation of the tungsten-binding protein for 1 h with 10 mM Na(2)WO(4) plus 10 mM metal ion, such as NaVO(3), Na(2)MoO(4), CuSO(4), NiSO(4), MnSO(4), CoSO(4), or CdCl(2), did not markedly affect the amount of tungsten bound to the tungsten-binding protein, suggesting that the protein specifically binds tungsten.
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PMID:Existence of a tungsten-binding protein in Acidithiobacillus ferrooxidans AP19-3. 1623 46

Two-dimensional fluorescence-based difference gel electrophoresis (DIGE) was used in combination with matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) to identify a set of hypoxia-related biomarker proteins in medaka (Oryzias latipes) brain tissue. Each of the proteins were identified via de novo sequencing of tryptic peptides derivatized with 4-sulfophenyl isothiocyanate (SPITC), which N-terminally sulfonates peptides and promotes facile post-source decay peptide fragmentation, resulting in greatly simplified spectra consisting mainly of y-series fragment ions. We also report that addition of the non-ionic surfactant n-octyl-beta-d-glucopyranoside significantly improves SPITC-derivatized peptide recoveries. In addition, we found that a MALDI matrix consisting of the sodium-tolerant matrix 2,4,6-trihydroxyacetophenone, diammonium citrate, and alpha-cyano-4-hydroxycinnamic acid also improves ionization of SPITC-peptides, presumably by reducing ionization suppression effects from matrix contaminants, especially sodium cations. The DIGE experiments and analyses resulted in detection of six abundant proteins and related isozymes up-regulated (>1.49, p<0.005) in hypoxic medaka brain tissues, including two hemoglobin beta subunit forms, four carbonic anhydrase 2 forms, calbindin, aldolase, succinate dehydrogenase, and glutathione-S-transferase.
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PMID:Detection of hypoxia-related proteins in medaka (Oryzias latipes) brain tissue by difference gel electrophoresis and de novo sequencing of 4-sulfophenyl isothiocyanate-derivatized peptides by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. 1690 68