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  • 1
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A leucine aminopeptidase was purified to homogeneity fromStreptomyces rimosus culture filtrates, which are waste broth of oxytetracycline bioproduction process. Purification procedure includes ultrafiltration and chromatography on CM-Sephadex, AH-Sepharose and FPLC Mono S column. The enzyme is a monomer with molecular weight of 27,500 Daltons and pI of 7.3, stable in broad pH range and up to 70°C. It is a metallo enzyme dependent on Ca2+ ions for its full activity. By its specificity it is a true aminopeptidase active on amino acid amide, arylamide, peptide and ester bonds. The hydrolysing activity shows preference for leucine at the N-terminal position of substrates, also acts on aromatic acids and methionine, but does not release glycine, proline, acidic amino acids orD-amino acid residues.
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  • 2
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A purification procedure for an extracellular α-amylase from Streptomyces rimosus, oxytetracycline-producing strain, is described. The enzyme obtained was shown to be an acidic (pI 4.75) monomer with a relative molecular mass (Mr) of 43 000, containing three cysteines involved in the catalytic activity of the enzyme. Its amino-terminal part has 57–67% homology with amylases from other Streptomyces species. S. rimosus α-amylase is sensitive to higher temperatures, and partially stabilized by Ca2+ ions. It hydrolyses starch (optimum at pH 5.0–6.0) in an endohydrolase manner giving rise to maltotriose, maltotetraose and higher oligosaccharides. Starch granules, except those from rice, were not significantly affected by the isolated α-amylase.
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  • 3
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract From filtrates of an oxytetracycline-producing culture of Streptomyces rimosus a deoxyribonuclease was purified to homogeneity and determined to be a potent endo-DNase. It is a monomeric, basic protein (Mr ≈ 21 000; pI ≈ 9.5) stable in a broad pH range but unstable to higher temperature. The enzyme has an absolute requirement for Mg2 + or Mn2 +, and for its full activity requires free SH groups and a low-ionic-strength environment. Its N-terminal primary structure differs from that of other nucleases.
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  • 4
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Streptomyces rimosus culture filtrates after oxytetracycline production were shown to contain a number of hydrolytic enzymes in concentrations high enough to indicate their exploatation. Crude enzyme preparations were obtained using precipitation, salting out and spray-drying methods. The presence of acid, neutral, and alkaline protease and their elastolytic, esterolytic and collagenolytic activities were discerned. Substrate specificity, pH and temperature optimum, pH stability and molecular weight were studied. These proteases belonged to the group of serine and metalloenzymes. Carboxyl and thiol proteases were not present.
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  • 5
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A trypsin-like proteinase was isolated from Streptomyces rimosus culture filtrates obtained from an oxytetracycline production process. The isolation procedure includes ultrafiltration, chromatography on CM-Sephadex, AH-Sepharose and CM-cellulose and gives a homogeneous protein with 19% yield. The enzyme is an anionic trypsin (Mr 28 000, pI 4.5), is stable from pH 4.5 to 9 and up to 40°C, and contains three disulphide bridges, three histidines and three methionines per molecule. At its pH optimum (pH 8.4–8.8) it splits peptide, ester and arylamide bonds of arginine in the endo-position and, to a smaller extent, in the exo-position. Like other streptomycete trypsins, it is a more efficient catalyst than bovine trypsin and has a relative preference for peptide-arylamides, Nα-benzyloxycarbonyl-l-norleucyl-l-prolyl-l-arginine-p-nitroanilide being by far its best substrate.
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  • 6
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A procedure for purification of a serine alkaline proteinase from Streptomyces rimosus waste broth was developed. The procedure includes ultrafiltration, CM-Sephadex C-50 and CM-cellulose chromatography and gel filtration on Sephadex G-75. The recovery of electrophoretically pure enzyme was 25%. The enzyme is active on different protein and synthetic substrates at neutral and alkaline pHs but its activity on hemoglobin and bovine serum albumin, is optimal at pH 4.0–4.5. It has a molecular weight of 22,000 and a pI of 4.90. The enzyme is inhibited by DFP and PMSF but not by TPCK. Its substrate specificity, amino acid composition and some other properties were also determined.
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