Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 107 kDa (pp107) casein kinase G (ck-G) substrate has been purified from mouse and beef thyroid cytosol; ck-G was purified from beef thyroid cytosol. Ck-G and pp107 were found to co-elute on DEAE cellulose chromatography at approximately 300 mM NaCl. Ck-G and pp107 were separated by spermine-agarose affinity chromatography; pp107 is eluted with a stepped gradient at 250 mM NaCl and ck-G is eluted at 500 mM NaCl. Ck-G was subsequently purified by casein-agarose and GTP-agarose affinity chromatography. The 107 kDa protein was purified using heparin-agarose affinity chromatography. Phosphorylation of purified pp107 by ck-G was stimulated by spermine (ED50 = 0.2 mM) and inhibited by low concentrations of heparin (0.1-5 micrograms/ml). The Km and Vmax for the reaction were 1.46 microM and 32.2 nmoles P transferred/20 min/mg protein, respectively; 1 mole pp107 incorporated 0.81 mole phosphorus. pp107 was found to be an acidic substrate with a pI of 3.87 and was absorbed to wheat-germ agglutinin-agarose. The specificity of pp107 phosphorylation was studied using diacylglycerol-activated calcium/phospholipid-dependent protein kinase C, calcium-activated calmodulin-dependent protein kinase, and the catalytic subunit of cAMP-dependent protein kinase A. Phosphorylation of pp107 by the other protein kinases tested never exceeded 4% of that of ck-G. Our data show that pp107 is an acidic glycoprotein which may serve as a high-affinity and specific substrate for ck-G.
Mol Cell Biochem 1988 Oct
PMID:Purification of a 107 kilodalton (kDa) casein kinase G substrate from thyroid cytosol. 320 Feb 52

Actin was identified in boar and mole spermatozoa by utilizing indirect immunofluorescence, immunoelectron microscopy, and SDS-PAGE, followed by blot and screening with an anti-actin monoclonal antibody. Actin was detected in two places in the sperm head: the equatorial segment of the acrosome and the postacrosomal region. The protein was present in a nonfilamentous form and was localized under the plasma membrane. A small amount of actin was also detected in the sperm tail. The function of actin in the sperm head is discussed.
J Ultrastruct Mol Struct Res
PMID:Localization and distribution of actin in mammalian sperm heads. 331 22

The relations between the single high affinity binding sites for azapropazone, phenylbutazone, chlorpropamide, sulfathiazole, and iophenoxate and the binding regions of human serum albumin represented by the marker ligands diazepam, phenol red, salicylate, and warfarin were examined by a series of competition experiments. Binding was determined by equilibrium dialysis at pH 7.0. In order to ensure an accurate analysis of the competition experiment, the number of moles of ligand bound per mole of protein was usually 0.4 or less to minimize ligand binding to weaker sites. Furthermore, binding of both ligands was determined in all experiments (except for iophenozate). None of the test ligands competed with diazepam for a common high affinity binding site, but, surprisingly, they were all able to displace two or three of the other marker ligands according to a competitive scheme. These findings show, first, the existence of a particular serum albumin region for high affinity binding of diazepam. Secondly, they imply that it is not necessary to assume the existence of new drug binding regions beyond those existing for phenol red, salicylate, and warfarin. On the contrary, the relatively many examples of competitive binding indicate that the binding regions represented by the last-mentioned three marker ligands are placed quite close to each other in the albumin molecule in a common region, which is suggested to be located at subdomains 1C and 2A-B. The region must be relatively large, because in some cases independent high affinity binding of pairs of ligands is observed. It is probably also rather flexible, inasmuch as no clear relation could be found between the chemical structure of the test ligands and the two or three marker ligands with which they compete. Correlations between primary association constants and partition coefficients for both marker ligands and test ligands, in the unionized forms, between n-hexane or 1-octanol and aqueous media showed that hydrophobic forces are important for the binding processes. However, the data also showed that other attractive forces must be operative as well.
Mol Pharmacol 1988 Aug
PMID:Evidence for a large and flexible region of human serum albumin possessing high affinity binding sites for salicylate, warfarin, and other ligands. 341 20

Cholesterol crystals activate the human alternative complement pathway. Loss of Factor B hemolytic activity in C2-deficient serum was comparable to that in normal human serum after incubation with cholesterol crystals. Consumption of Factor B hemolytic activity in normal serum incubated with cholesterol occurred in a time- and dose-dependent manner. The reduced capacity of crystals-absorbed serum to activate C2, but not Factor B, on fresh crystals, indicated that cholesterol mediates antibody-dependent classical pathway activation in addition to alternative pathway activation in whole serum. Cholestane triol, an oxidation derivative of cholesterol which bears three hydroxyl groups, cleaved 5-fold more C3 than cholesterol in normal human serum. Three cholesterol derivatives, each bearing two hydroxyl groups, were intermediate activators between cholesterol and cholestane triol. The compounds differed, however, in their complement-activating ability, indicating that hydroxyl position as well as number exerts an influence on complement activation. Measurements of C3adesArg and C5adesArg antigens in cholesterol crystal treated serum revealed that approx. 10% of total serum C3 was cleaved and that, on a molar basis, only 3% C5 cleavage occurred relative to C3 cleavage. For 1 mole of C5a generated, 0.1 moles of fluid-phase C5b-9 was detected. Although the extent of C3 cleavage varied with each cholesterol derivative depending on the position and number of hydroxyl groups, the relative coupling efficiency of C3 and C5 cleavage and C5a and C5b-9 generation was similar for all compounds. The ability of cholesterol and its oxidation products to generate anaphylatoxins and C5b-9 complexes may be of importance in mediating inflammatory processes involved in atherogenesis.
Mol Immunol 1987 Dec
PMID:Generation of complement anaphylatoxins and C5b-9 by crystalline cholesterol oxidation derivatives depends on hydroxyl group number and position. 343 52

Hemin catalyses the oxidation of dithiothreitol. One mole of oxygen is consumed for every 2 moles of dithiothreitol oxidized and the product is shown by spectral studies to be the intramolecular disulphide. The reaction shows a specificity for dithiol and for free heme moieties. Hemin molecules exhibit cooperativity in oxygen reduction. Oxygen radicals do not seem to be involved. H2O2 is not required for this oxidation of dithiothreitol and does not appear to be an intermediate in the reduction of O2 to H2O. However, an independent minor reaction involving a 2-electron transfer with the formation of H2O2 also occurs. These studies on the hemin-catalyzed oxidation of dithiothreitol provide a chemical model for a direct 4-electron reduction of O2 to H2O.
Mol Cell Biochem 1987 Oct
PMID:Hemin-mediated oxidation of dithiothreitol reduces oxygen to H2O. 343 84

A cosmid genomic library was prepared from a single individual of the rodent Spalax ehrenbergi, the mole rat, captured in Israel. The library was screened with a mouse probe hybridizing with all mouse class I major-histocompatibility-complex (Mhc) genes; the cross-hybridizing clones were isolated; and their restriction maps were prepared using five enzymes. A total of 93 class I-bearing clones could be identified in the library. Forty-five of these clones showed partial overlaps and could be arranged into 14 clusters. Eleven of these clusters could be shown to contain two class I genes each; the remaining clusters, as well as most of the non-overlapping clones, each contained one class I gene. After the elimination of clones with possible cloning artifacts and of clones that may carry allelic forms of a given gene in the heterozygous animal, the total number of class I loci identified in Spalax is approximately 65. The high number of loci probably arose from the duplication of either the entire class I set or the different class I families. The high number of gene copies might represent a means of selecting different functional genes from the family in different mammalian orders. Three of the approximately 65 Spalax class I genes cross-hybridize with a probe specific for the mouse K, D, and L genes; two of these genes are in the same cluster. These three elements might possibly be the functional class I genes of the mole rat.
Mol Biol Evol 1987 Sep
PMID:Evolutionary expansion of Mhc class I loci in the mole-rat, Spalax ehrenbergi. 344 37

The ability of purified bovine neurointermediate pituitary peptidyl glycine alpha-amidating monooxygenase to catalyze the conversion of peptide substrates (D-Tyr-X-Gly) into amidated product peptides (D-Tyr-X-NH2) was evaluated. The pH optimum of the reaction was pH 8.5 when X was Val, Trp, or Pro, but 5.5 to 6.0 when X was Glu. Similar maximum velocity (Vmax) values were obtained for the Val, Trp, and Pro substrates while the Glu substrate had a substantially higher Vmax. The Michaelis-Menten constant (Km) of the enzyme for the peptide substrate increased in the order Trp less than Val less than Pro much less than Glu. Increasing levels of ascorbate brought about parallel increases in Km and Vmax, suggesting the presence of an irreversible step separating the interaction of the enzyme with the two substrates. The effect of copper on enzyme activity was dependent on the peptide substrate and the reaction pH. With the Val substrate, exogenous copper was required for optimal activity; no other metal ion tested could substitute for copper. With the Glu substrate, exogenous copper was not required for optimal activity; however, diethyldithiocarbamate, a copper chelator, inhibited activity and only copper could reverse this inhibitory effect. The ability of various cofactors to stimulate alpha-amidating monooxygenase activity was also dependent on assay conditions. With the Val or Glu substrate in the presence of exogenous copper, a variety of cofactors in addition to ascorbate were capable of supporting activity. With the Glu substrate in the absence of exogenous copper, the requirement of the enzyme for ascorbate was more strict. In keeping with the proposed reaction mechanism, nearly 1 mol ascorbate was consumed for each mole of D-Tyr-Glu-NH2 produced.
Mol Endocrinol 1987 Apr
PMID:Further characterization of peptidylglycine alpha-amidating monooxygenase from bovine neurointermediate pituitary. 345 94

Using the semiempirical MNDO method, several systems simulating the active site of serine proteases have been studied. The stabilization energy was found to depend strongly on the nucleophilicity of the attacking group. The decrease of the activation energy has been estimated as 9 kcal/mole. It was shown that the substrate distortion does not vary with forming of hydrogen bonds.
Mol Biol (Mosk)
PMID:[Evaluation of the energy of the stabilization of the transitional state due to hydrogen bonds in the active site of serine proteases]. 348 22

An in vitro red blood cell assay (RBC assay) is presented that allows one to estimate irritation potentials of tensides and detergents. The estimation is based on the differentiation between cell membrane lysis and cell protein denaturation. Both effects are measured photometrically by use of the inherent native dye oxyhemoglobin (HbO2). Besides hemolysis (H50) as a test parameter, the denaturation index DI is introduced, which is defined to be equal to 100% at a concentration of 30 mol sodium dodecylsulfate (SDS) per mole HbO2 as internal standard. The HbO2 release (H50), its denaturation (DI), and the ratio of both parameters (L/D ratio) are used to characterize the in vitro effects of surfactants. All data, including the L/D ratio are compared with in vivo data on eye irritancies, evaluated according to OECD Guideline #405 for testing chemicals, and with other published results from in vivo experiments. The good correlation of the L/D ratio of a broad range of 100 marketable shampoos with their corresponding Draize data (r = .806, p less than .0001) allows one to predict eye irritation potentials from another 20 commercially available shampoos in a blind trial with highly significant rank correlations to their in vivo irritancies (rs = .911, p less than .0001). Nearly similar good correlations were obtained by comparing ranks of in vivo and in vitro data of 16 anionic surfactants. All correlations found were significant (rs greater than .80 and p less than .0001). The RBC assay is an inexpensive, rapid, irritancy screening test that provides reliable results with good reproducibility. The test helps to reduce or even avoid animal testing in this application.
Mol Toxicol
PMID:Validation of the red blood cell test system as in vitro assay for the rapid screening of irritation potential of surfactants. 350

The interaction of glyceraldehyde 3-phosphate dehydrogenase with microtubules has been studied by measurement of the amount of enzyme which co-assembles with in vitro reconstituted microtubules. The binding of glyceraldehyde 3-phosphate dehydrogenase to microtubules is a saturable process; the maximum binding capacity is about 0.1 mole of enzyme bound per mole of assembled tubulin. Half saturation of microtubule binding sites is obtained at a concentration of glyceraldehyde 3-phosphate dehydrogenase of about 0.5 microM. Glyceraldehyde 3-phosphate dehydrogenase (between 0.1 and 2 microM) induces a concentration-dependent increase a) in the turbidity of the microtubule suspension without alteration of the net amount of polymer formed and b) in the amount of microtubule protein polymers after cold microtubule disassembly. There is a linear relationship between the intensity of the glyceraldehyde 3-phosphate dehydrogenase-induced effects and the amount of microtubule-bound enzyme. The specificity of the association of glyceraldehyde 3-phosphate dehydrogenase to microtubules has been documented by copolymerization experiments. Assembly-disassembly cycles of purified microtubules in the presence of a crude liver soluble fraction results in the selective extraction of a protein with an apparent molecular weight of 35,000 identified as the monomer of glyceraldehyde 3-phosphate dehydrogenase by peptide mapping and immunoblotting. In conclusion, microtubules possess a limited number of binding sites for glyceraldehyde 3-phosphate dehydrogenase. The binding of the glycolytic enzyme to microtubules shows a considerable specificity and is associated with alterations of assembly and disassembly characteristics of microtubules.
Mol Cell Biochem 1987 Mar
PMID:Binding of glyceraldehyde 3-phosphate dehydrogenase to microtubules. 358 30


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