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)

A sialidase from Bacteroides fragilis SBT3182 was purified 2,240-fold to apparent homogeneity by ammonium sulfate precipitation and sequential chromatographies on DEAE-Toyopearl 650M, Hydroxyapatite, MonoS and Superose6 columns. The N-terminal amino acid sequence of this sialidase, Ala-Asp-X-Ile-Phe-Val-Arg-Glu-Thr-Arg-Ile-Pro-, was determined. Substrate specificity of this enzyme using a variety of sialoglycoconjugates showed a 1.5- and 2.2-fold preference for sialyl alpha 2-8 linkages when compared with alpha 2-3 and alpha 2-6 bound sialic acids, respectively. The native sialidase had a molecular weight of 165kDa, as determined by Superose6 gel filtration chromatography and consisted of three subunits each of 55kDa by SDS-polyacrylamide gel electrophoresis. This enzyme had optimal activity at pH6.1 with colominic acid as substrate.
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PMID:Purification and characterization of a sialidase from Bacteroides fragilis SBT3182. 133 98

The first representative of a group of mammalian, low molecular weight phosphotyrosyl protein phosphatases was cloned, sequenced and expressed in Escherichia coli. Using a 61-mer oligonucleotide probe based on the amino acid sequence of the purified enzyme, several overlapping cDNA clones were isolated from a bovine heart cDNA library. A full-length clone was obtained consisting of a 27-bp 5' noncoding region, an open reading frame encoding the expected 157 amino acid protein, and an extensive 3' nontranslated sequence. The identification of the clone as full length was consistent with results obtained in mRNA blotting experiments using poly(A)+ mRNA from bovine heart. The coding sequence was placed downstream of a bacteriophage T7 promoter, and protein was expressed in E. coli. The expressed enzyme was soluble, and catalytically active and was readily isolated and purified. The recombinant protein had the expected Mr of 18,000 (estimated by SDS-PAGE), and it showed cross-reactivity with antisera that had been raised against both the bovine heart and the human placenta enzymes. The amino acid sequence of the N-terminal region of the expressed protein showed that methionine had been removed, resulting in a sequence identical to that of the enzyme isolated from the bovine tissue, with the exception that the N-terminal alanine of the protein from tissue is acetylated. A kinetically competent phosphoenzyme intermediate was trapped from a phosphatase-catalyzed reaction. Using 31P NMR, the covalent intermediate was identified as a cysteinyl phosphate. By analogy with the nomenclature used for serine esterases, these enzymes may be called cysteine phosphatases.
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PMID:Cloning, expression, and catalytic mechanism of the low molecular weight phosphotyrosyl protein phosphatase from bovine heart. 133 87

A new type of IL-2(Ser-125) was purified by semi-preparative RP-HPLC, and its purity was analyzed with microbore HPLC, IEF, SDS-PAGE and capillary electrophoresis (CE). The N-terminal sequencing indicated the microheterogeneity of the N-terminus, i.e., N-Met(2/3) and N-Ala(1/3), which was identified with the results of CE and IEF. The amino acid sequence of the point mutated peptide confirmed the replacement of Cys-125 with Ser.
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PMID:Purification and point-mutation analysis of human interleukin-2 (Ser-125). 134 25

Arylsulfatase A purified from human placenta contained an unreported component with an apparent molecular mass of 7 kDa in addition to the two known components with apparent molecular masses of 58 and 50 kDa. The detailed relationship between the 58 kDa component and the 50 kDa component is as yet unknown. The present study was undertaken to define the structure of the subunits of the sulfatase. The N-terminal sequence of the 50 kDa component was identical to that of the 58 kDa component. Furthermore, the peptide maps of the 50 kDa component, which was separately digested with trypsin and Achromobacter proteinase I, were quite similar to those of the 58 kDa one. Through sequence analysis of the incompatible peaks in the peptide maps, the 50 kDa component was found to lack a sequence from Val-445 to the C-terminus. On the other hand, the N-terminal sequence of the 7 kDa component began with Ala-448, though there was a minor sequence commencing with Thr-449. These observations suggest that the 50 and 7 kDa components were produced by limited proteolysis near the C-terminus of the 58 kDa component. Through analysis using unreducing SDS-PAGE, the 58 and the 7 kDa components were found to be linked by disulphide bonds. Arylsulfatase A purified from human liver was also composed of the same subunits as the placental one. This finding suggests that human arylsulfatase A undergoes similar proteolytic processing regardless of the tissue involved.
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PMID:Proteolytic processing of human lysosomal arylsulfatase A. 135 93

Structural studies assessed interactions between the amino-terminal peptide (FP-I; 23 residues 519-541) of the glycoprotein 41,000 (gp41) of Human Immunodeficiency Virus Type-1 (HIV-1) and human erythrocyte membranes and simulated membrane environments. Peptide binding was examined at sub-hemolytic (approx. less than 5 microM) and hemolytic (greater than or equal to 5 microM) doses (Mobley et al. (1992) Biochem. Biophys. Acta 1139, 251-256), using circular dichroism (CD) and Fourier-transform infrared (FTIR) measurements with FP-I, and electron spin resonance (ESR) studies employing FP-I spin-labeled at either the amino-terminal alanine (FP-II; residue 519) or methionine (FP-III; position 537). In the sub-lytic regime, FP-I binds to both erythrocyte lipids and dispersions of SDS with high alpha-helicity. Further, ESR spectra of FP-II labeled erythrocyte ghosts indicated peptide binding to both lipid and protein. In ghost lipids, FP-II was monomeric and exhibited low polarity and rapid, anisotropic motion about its long molecular axis (i.e., alpha-helical axis), with restricted motion away from this axis. The spin-label at the amino-terminal residue (Ala-519) is insensitive to the aqueous broadening agent chromium oxalate and buried within the hydrophobic core of the membrane; the angle that the alpha-helix (residues 519-536) makes to the normal of the bilayer plane is either 0 degree or 40 degrees. Contrarily, ESR spectra of ghost lipids labeled with sub-lytic doses of FP-III indicated high mobility and polarity for the reporter group (Met-537) at the aqueous-membrane interface, as well as extreme sensitivity to chromium oxalate. At lytic FP-I doses, CD and FTIR showed both alpha-helix and beta-structure for peptide in ghost lipids or detergent, while ESR spectra of high-loaded FP-II in ghost membranes indicated peptide aggregates. Membrane aggregates of FP-I may be involved in hemolysis, and models are suggested for N-terminal gp41 peptide participation in HIV-induced fusion and cytolysis.
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PMID:The amino-terminal peptide of HIV-1 glycoprotein 41 interacts with human erythrocyte membranes: peptide conformation, orientation and aggregation. 135 64

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

Protease secreted into the culture medium by alkalophilic Thermoactinomyces sp. HS682 was purified to an electrophoretically homogeneous state through only two chromatographies using Butyl-Toyopearl 650M and SP-Toyopearl 650S columns. The purified enzyme has an apparent relative molecular mass of 25,000 according to gel filtration on a Sephadex G-75 column and SDS-PAGE and an isoelectric point above 11.0. Its proteolytic activity was inhibited by active-site inhibitors of serine protease, DFP and PMSF, and metal ions, Cu2+ and Hg2+. The enzyme was stable toward some detergents, sodium perborate, sodium triphosphate, sodium-n-dodecylbenzenesulfonate, and sodium dodecyl sulfate, at a concentration of 0.1% and pH 11.5 and 37 degrees C for 60 min. The optimum pH was pH 11.5-13.0 at 37 degrees C and the optimum temperature was 70 degrees C at pH 11.5. Calcium divalent cation raised the pH and heat stabilities of the enzyme. In the presence of 5 mM CaCl2, it showed maximum proteolytic activity at 80 degrees C and stability from pH 4-12.5 at 60 degrees C and below 75 degrees C at pH 11.5. The stabilization by Ca2+ was observed in secondary conformation deduced from the circular dichroic spectrum of the enzyme. The protease hydrolyzed the ester bond of benzoyl leucine ester well. The amino acid terminal sequence of the enzyme showed high homology with those of microbial serine protease, although alanine of the NH2-terminal amino acid was deleted.
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PMID:Purification and characterization of a thermostable alkaline protease from alkalophilic Thermoactinomyces sp. HS682. 136 1

Pseudomonas stutzeri MO-19 produced two active forms of extracellular maltotetraose-forming amylase. Both forms, G4-1 and G4-2, were purified to electrophoretic homogeneity. The molecular masses of G4(-1) and G4(-2) were 57 kd and 46 kd by SDS-polyacrylamide gel electrophoresis, respectively. An identical N-terminal sequence up to 20 amino acid residues and similar amino acid compositions were obtained from both forms, but different C-terminal amino acids, leucine from G4(-1) and alanine from G4(-2), were released by carboxypeptidase Y. By in vitro incubation with a culture supernatant containing protease activity, G4(-1) was converted into G4(-2) without any loss of the amylase activity. It was concluded that G4(-2) was a product derived by the limited proteolysis of G4(-1), and that the proteolysis occurred in the C-terminal region of G4-1. G4-2 was more thermostable than G4(-1), and had a 20-fold higher Michaelis constant value for glycogen, which was 50 mg/ml against 2.3 mg/ml of G4(-1). G4(-1) adsorbed onto raw starch granules while G4(-2) did not.
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PMID:Purification and characterization of two forms of maltotetraose-forming amylase from Pseudomonas stutzeri. 136 35

The enzymatically inactive but raw-starch-adsorbable peptide fragments designated as Gp-pan P and Gp-pan I were obtained from a tryptic digest of heat-inactivated hog pancreatic alpha-amylase. These two glycopeptide fragments were purified with Sephadex G-75, DEAE-Sephadex A-50, and HPLC and were found to be homogeneous on disc gel electrophoresis. Gp-pan P and I had molecular weights of 20,000 and 30,000 with SDS-PAGE, carbohydrate contents of 10% and 7%, N-terminal amino acids Gly-Trp and Ala-Val, and C-terminal amino acids Gly-Arg and Ile-Lys. Gp-pan P had promotive but Gp-pan I inhibitory effects on raw starch digestion by Aspergillus awamori var. kawachi glucoamylase I and Bacillus subtilis 65 alpha-amylase.
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PMID:Promotive and inhibitory effects of raw starch adsorbable fragments from pancreatic alpha-amylase on enzymatic digestions of raw starch. 136 57

Aminopeptidase C was purified from fresh chicken skeletal muscle by ammonium sulfate fractionation, and by successive chromatography on DEAE-cellulose, Ultrogel AcA 34, DEAE-cellulose again, and an alanine AH-Sepharose 4B affinity column twice. The purified enzyme migrated as a single band by SDS-PAGE. Aminopeptidase C was purified about 300-fold over the crude extract with a yield of 0.6%. The molecular weight of this enzyme was found to be 185,000 by gel filtration in a Sepharose 6B column and 92,000 by SDS-PAGE. The optimum pH for the hydrolysis of L-leucine beta-naphthylamide was 6.0-7.0, the enzyme being stable in the range of pH 6.5-8.0. The activity of this enzyme was strongly inhibited by EDTA and puromycin, and was high against the beta-naphthylamide derivatives of Lys, Leu, Ala and Met. The enzyme was more active towards tri- and tetrapeptides than towards dipeptides.
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PMID:Purification and properties of aminopeptidase C from chicken skeletal muscle. 136 17


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