Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Administration of 17beta-estradiol to roosters induced the synthesis of vitellogenin in the liver. The mRNA that specifies this protein has been purified from the livers of estrogen-treated roosters and has been shown to have a molecular weight of 2.3 X 10(6) (Deeley, R.G., Gordon, J.I., Burns, A.T.H., Mullinix, K.P., Bina-Stein, M., and Goldberger R.F. (1977) J. Biol. Chem. 252, 8310-8319). In order to rigorously establish the identity of the polypeptide specified by this mRNA, we used a staphylococcal nuclease-treated, mRNA-dependent wheat germ cell-free translation system capable of synthesizing polypeptides as large as vitellogenin (monomer Mr = 240,000). Vitellogenin mRNA directs the in vitro synthesis of a polypeptide with the following features: (a) it co-migrates with authentic vitellogenin in SDS-polyacrylamide gels; (b) it is highly enriched for serine but is not phosphorylated; (c) it is immunoprecipitated by purified, monospecific, anti-vitellogenin antibody; and (d) it has an unusual cyanogen bromide cleavage pattern characteristic of vitellogenin. The most striking characteristic of the cyanogen bromide cleavage products is an extremely large polypeptide (Mr = 90,000) that contains two phosvitins. The kinetics of incorporation of serine and methionine into vitellogenin synthesized in the wheat germ cell-free translation system indicates that the phosvitins are located near the COOH-terminal portion of the molecule.
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PMID:In vitro translation of avian vitellogenin messenger RNA. 91 74

The effect was determined of replacing medium inorganic phosphate with thiophosphate on the structure and function of cultured bovine chromaffin cells. Cell cultures were incubated in normal medium containing fetal bovine serum, phosphate free medium or similar medium supplemented with inorganic phosphate or thiophosphate. In contrast to the other media, cells cultured with thiophosphate medium for 3-4 days showed seriously compromised structure and functions. The cells lost 75% of their catecholamine content and their ability to secrete remaining catecholamines in response to nicotine stimulation. Radiolabelled thiophosphate was rapidly taken up by the cells and, in long-term experiments, was incorporated largely into a 97-121 kDa protein band on SDS-PAGE. Additional minor bands were found to a lesser, variable extent. Transmission electron micrographs of cells treated with thiophosphate showed extensive depletion of chromaffin vesicles and disruption of mitochondria, suggesting that the functional damage noted with these cells could be associated with damage to mitochondria. Analysis of general cell metabolic activity by conversion of the dye (3-[3,4-dimethylthiazol-2-yl]-3,5-diphenyltetrazolium bromide) to its formazan derivative indicated increased metabolic activity at early stages of exposure to thiophosphate followed by a decline with continued exposure, supporting the argument for an overall depression of cell metabolism. Uptake of the dye neutral red, which is avidly accumulated by chromaffin cells, was also reduced for cells exposed to thiophosphate. The data suggest that thiophosphate enters chromaffin cells and disrupts energy dependent cell functions, including catecholamine storage and secretion.
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PMID:Inorganic thiophosphate effects on chromaffin cell structure and function. 130 67

The major outer membrane protein of Legionella pneumophila exhibits an apparent molecular mass of 100 kDa. Previous studies revealed the oligomer to be composed of 28- and 31-kDa subunits; the latter subunit is covalently bound to peptidoglycan. These proteins exhibit cross-reactivity with polyclonal anti-31-kDa protein serum. In this study, we present evidence to confirm that the 31-kDa subunit is a 28-kDa subunit containing a bound fragment of peptidoglycan. Peptide maps of purified proteins were generated following cyanogen bromide cleavage or proteolysis with staphylococcal V8 protease. A comparison of the banding patterns resulting from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed a common pattern. Selected peptide fragments were sequenced on a gas phase microsequencer, and the sequence was compared with the sequence obtained for the 28-kDa protein. While the amino terminus of the 31-kDa protein was blocked, peptide fragments generated by cyanogen bromide treatment exhibited a sequence identical to that of the amino terminus of the 28-kDa protein, but beginning at amino acid four (glycine), which is preceded by methionine at the third position. This sequence, (Gly-Thr-Met)-Gly-Pro-Val-Trp-Thr-Pro-Gly-Asn ... , confirms that these proteins have a common amino terminus. An oligonucleotide synthesized from the codons of the common N-terminal amino acid sequence was used to establish by Southern and Northern (RNA) blot analyses that a single gene coded for both proteins. With regard to the putative porin structure, we have identified two major bands at 70 kDa and at approximately 120 kDa by nonreducing SDS-PAGE. The former may represent the typical trimeric motif, while the latter may represent either a double trimer or an aggregate. Analysis of these two forms by two-dimensional SDS-PAGE (first dimensions, nonreducing; second dimensions, reducing) established that both were composed of 31- and 28-kDa subunits cross-linked via interchain disulfide bonds. These studies confirm that the novel L. pneumophila major outer protein is covalently bound to peptidoglycan via a modified 28-kDa subunit (31-kDa anchor protein) and cross-linked to other 28-kDa subunits via interchain disulfide bonds.
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PMID:Molecular characterization of the 28- and 31-kilodalton subunits of the Legionella pneumophila major outer membrane protein. 131 95

Proteins in human red cell hemolysate were purified to determine which of them increase inhibition of the Na,K-ATPase in the presence of 2 microM free Ca. Samples purified 600,000-fold inhibited the Na,K-ATPase of human red cells in a Ca-dependent manner and stimulated the (Ca+Mg)-ATPase. These samples contained two proteins as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE): calmodulin (18,000 Mr), which comprised most (greater than 90%) of the total protein, and an unidentified protein of approximately 13,000 Mr. Both proteins were a distinctive light yellow when stained with silver. Calmodulin from bovine testes also inhibited the Na,K-ATPase and stimulated the (Ca+Mg)-ATPase. This preparation also contained two proteins as analyzed by SDS-PAGE: calmodulin (95 to 99% of the total protein) and another protein of approximately 13,000 Mr (1 to 5% of the total protein). Both were light yellow when stained with silver. Since the amount of red cell protein was limited, the remainder of the study was carried out with the bovine testes preparation. Heating the testes preparation decreased, but did not abolish, inhibition of the Na,K-ATPase and reduced stimulation of the (Ca+Mg)-ATPase. When corrected for denatured calmodulin, both heated and unheated proteins increased inhibition of the Na,K-ATPase to the same extent. The Na,K-ATPase was inhibited at 2 microM free Ca in a dose-dependent manner over a range of 15 to 100 nM calmodulin. To establish if the inhibition was due to the calmodulin or the 13,000 Mr protein, both were electroeluted after SDS-PAGE. Electroeluted calmodulin stimulated the (Ca+Mg)-ATPase and increased Ca inhibition of the Na,K-ATPase. Electroeluted amounts of the smaller Mr protein slightly stimulated the (Ca+Mg)-ATPase, but had no effect on the Na,K-ATPase. This protein was digested with cyanogen bromide, partially sequenced, and thereby identified as a fragment of calmodulin. We conclude that intact calmodulin increases inhibition of the Na,K-ATPase at 2 microM free Ca. We suggest that calmodulin is part of a mechanism mediating the effects of physiological free Ca on the Na,K-ATPase.
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PMID:Calmodulin increases Ca-dependent inhibition of the Na,K-ATPase in human red blood cells. 131 6

The pH values in reversed micelles were measured, making use of the hydrogenase enzyme as redox catalyst short-circuiting the viologen oxidized/semiquinone redox states. The hydrogenases from Desulfovibrio vulgaris (Hildenborough) and from Megasphaera elsdenii were applied. The observed pH values in reversed micelles were not dependent on the type of hydrogenase. Two cationic [cetyltrimethylammonium bromide and dodecylammonium propionate (DAP)] and two anionic sodiumdodecyl sulphate, sodium di(ethylhexyl)sulfosuccinate types of reversed micelles were used in combination with viologens having distinguishable valencies. It was observed that, in the cationic-reversed micelles, the dissociation constant for the semiquinone dimer had about the same value as compared to bulk water, while this value was significantly higher in the anionic-reversed micelles. Furthermore, the dissociation constant was independent of the concentration of viologen semiquinone in the reversed micelle, indicating that exchange kinetics are faster than the dimerisation process. With the exception of DAP, a linear relation exists, pH = a.pHrm + b, between the pH of the bulk water and the pH as measured in the reversed micelle (pHrm). In all these cases the value of a is smaller than unity, the value of b ranges between 1.6-2.7. For DAP the pHrm is always around 7. In DAP-reversed micelles, the counter-ion propionate probably serves as an internal buffer. Using cytochrome c3 as pH indicator in combination with N,N'-di(3-aminopropyl)-4,4'-bipyridinium)4+ to take care of electron transfer, in cetyltrimethylammonium-bromide-reversed micelles the pHrm is about the same as indicated by the viologen; in SDS-reversed micelles the pHrm is always lower than that indicated by N,N'-di(3-aminopropyl)4,4'-pyridinium4+. In contrast to cytochrome c3 from D. vulgaris, which in reversed micelles cannot become reduced directly by its D. vulgaris hydrogenase, the hydrogenase of M. elsdenii is able to reduce its ferredoxin directly.
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PMID:The pH in reversed micelles as imposed by the dihydrogen/proton redox couple and indicated by viologens and cytochrome c3 using hydrogenase as redox catalyst. 132 16

As aminoguanidine (AG) is known to prevent non-enzymatic glycosylation in various tissues, we have histologically and biochemically evaluated AG effects on the skin in control, SZ-diabetic and AG-treated (25 mg/kgbw/day, 10w) diabetic rats. HbA1c and plasma glucose levels in diabetic and AG-treated diabetic rats were maintained about two times higher than those in control rats during the 10 weeks of the experiment. Histological findings revealed that the dermis in diabetic rats was thin and edematous, associated with swelling and degeneration of collagen fibers. Necrobiotic changes were seen in the lower dermis. These changes were greatly improved in AG-treated diabetic rats. Skin glucose contents in diabetic and AG-treated diabetic rats were about 10 times higher than those in the controls, whereas there was no difference in the sorbitol contents between three groups. Dry weight of the skin and collagen content was well correlated (r = 0.9044) and collagen represented 78.0 +/- 2.3% of the dry weight. By SDS-PAGE analysis of cyanogen bromide digests it was shown that high molecular weight peptides were increased in diabetic rats, but were decreased in AG-treated diabetic rats. The mean of glycosaminoglycan (GAG) contents of diabetic skin was 54% of that in the controls (1.58 +/- 0.09 vs. 2.94 +/- 0.39 micrograms/mg dry weight, P < 0.0025), which increased significantly in AG-treated diabetic rats (1.75 +/- 0.07 microgram/mg dry weight, P < 0.01 vs. diabetic).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Amelioration of dermal lesions in streptozotocin-induced diabetic rats by aminoguanidine. 134 7

Glucose isomerase from Streptomyces phaeochromogenes was purified from a commercial preparation, Swetase, by DEAE-cellulose, Bio-Gel A-0.5 m, and hydroxyapatite column chromatographies. It was found to be 2 fractions; F-A, not adsorbed on hydroxyapatite and F-B, adsorbed on hydroxyapatite. They were homogeneous in ordinary and SDS-PAGE and had similarities in some enzymatic and physico-chemical properties. The differences, however, were found in the N-terminal amino acid, which was only serine for F-A while it was serine and alanine for F-B, and also in their peptide mapping patterns of digests with trypsin, Achromobacter protease I, and cyanogen bromide. The results suggest that glucose isomerase from S. phaeochromogenes was composed of the two kinds of isozymes and that each of isozymes was a tetramer constituted of non-identical subunits.
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PMID:Evidence for the existence of isozymes of glucose isomerase from Streptomyces phaeochromogenes. 136 94

A functional ovalbumin-dextran conjugate was prepared by dry-heated storage at 60 degrees C and 65% relative humidity for 3 weeks. The emulsifying properties of the ovalbumin-dextran conjugate were about three times higher than those of an ovalbumin-glucose conjugate. SDS-electrophoresis patterns showed that the ovalbumin-dextran conjugate obtained by dry-heating was not as polydispersed as that obtained by cyanogen bromide-activated dextran. The average molecular weight of the ovalbumin-dextran conjugate was about 200,000. The excellent emulsifying properties of ovalbumin-dextran conjugate were maintained even at pH 3 and were further improved at pH 10. In addition, the emulsifying properties of the ovalbumin-dextran conjugate were greatly enhanced by preheating the conjugate at 100 degrees C. Thus, it is suggested that an ovalbumin-dextran conjugate prepared by controlled dry-heating can be used as a macromolecular emulsifier for food applications.
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PMID:Functional protein-polysaccharide conjugate prepared by controlled dry-heating of ovalbumin-dextran mixtures. 136 84

C57BL/6 mice show thyroid lesions when immunized with porcine thyroid peroxidase (pTPO) emulsified in CFA. We attempted to clarify a thyroiditogenic epitope on pTPO. Thyroid peroxidase treated with cyanogen bromide was fractionated by reverse phase chromatography, and six fractions (A to F) were obtained. Two of these fractions (D and E) stimulated lymph node cells (LNC) primed with pTPO in vitro and induced thyroiditis in vivo. Tricine-SDS-PAGE and rechromatography showed that fraction D consisted solely of a fragment of Mr 9500 Da and that fraction E contained mainly fragments of Mr of 5400 and 9500 Da. The fragment of fraction D was rechromatographed and 20 NH2-terminal amino acids were analyzed. This segment was found to correspond to residue 726-745 of pTPO deduced from cDNA at a probability of 80%. Four peptides ranging from residue 746-827 were first synthesized and tested for their thyroiditogenicity. Only Pep-2 (29 amino acids) could stimulate LNC primed with pTPO and induce thyroiditis. Pep-2 was divided into two smaller peptides (Pep-2-1 and -2-2) and their thyroiditogenicity was tested again. Pep-2-1 corresponding to residue 774-788, GPA-QITCTPRGWDSP, had thyroiditogenicity as well as the ability to stimulate LNC. It was thought that this segment was at least one of the thyroiditogenic epitopes on porcine thyroid peroxidase for C57BL/6 mice.
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PMID:Identification of thyroiditogenic epitope on porcine thyroid peroxidase for C57BL/6 mice. 137 23

Treatment of spinach thylakoids with 1-ethyl-3-(dimethylaminopropyl)-carbodiimide (EDC)/N-hydroxysulfosuccinimide (sulfo-NHS) induced formation of a zero-length crosslink of an apparent molecular mass of 38 kDa. This product was shown, by immunodetection, to consist of subunit delta of CF1 and subunit I of CF0. The crosslink was isolated by preparative SDS gel electrophoresis and subjected to cyanogen bromide cleavage. Electrophoretic and immunological analysis of the resulting peptides suggested that the crosslink was formed between a glutamyl or aspartyl residue at the C-terminal end of subunit I and a basic amino acid of subunit delta in the range between Val-1 to Met-165. Treatment of thylakoids with EDC/Sulfo-NHS resulted in inhibition of photophosphorylation and CF0CF1-catalyzed ATP hydrolysis without affecting formation of a proton gradient related to phenazine methosulfate-mediated cyclic electron transport. Inhibition of H+ transport-coupled ATP hydrolysis was more pronounced than non-coupled methanol-stimulated ATP hydrolysis. The results suggest that subunits delta and I form a connection between the partial complexes CF1 and CF0 in situ. Crosslinking of the two subunits may impede the translocation of protons through CF0CF1.
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PMID:Zero-length crosslinking between subunits delta and I of the H(+)-translocating ATPase of chloroplasts. 138 76


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