scholarly journals The purification and properties of two staphylolytic enzymes from Streptomyces griseus

1968 ◽  
Vol 106 (1) ◽  
pp. 69-76 ◽  
Author(s):  
J. B. Ward ◽  
H R Perkins
Keyword(s):  
Molecular Weight ◽  
Cell Walls ◽  
Teichoic Acid ◽  
Streptomyces Griseus ◽  
Low Molecular Weight ◽  
Whole Cells ◽  
Ph Values ◽  
Purification And Properties ◽  
Soil Isolate ◽  
Isolated Cell

1. Two staphylolytic enzymes have been purified from cultures of a soil isolate of Streptomyces griseus. 2. The purified enzymes were shown to be basic proteins of low molecular weight. Each enzyme released N-acetylmuramic acid reducing groups from the cell walls of Staphylococcus aureus. 3. The enzymes lysed whole staphylococci best at higher pH values and lower ionic strengths than when the substrate was isolated cell walls or purified mucopeptide. 4. Added teichoic acid did not inhibit the enzymes, but it formed an ethanol-precipitable complex with them. 5. The possibility that teichoic acid on the surface of whole cells prevents the access of the enzymes to their mucopeptide substrate is discussed.

scholarly journals Purification and properties of a phytase from Candida melibiosica 2491

2018 ◽  
Author(s):  
Danail Georgiev ◽  
Georgi Dobrev ◽  
Stefan Shilev
Keyword(s):  
Molecular Weight ◽  
Copper Ions ◽  
Phytase Activity ◽  
Gel Chromatography ◽  
Experimental Conditions ◽  
Cobalt Ions ◽  
Whole Cells ◽  
Inhibition Effect ◽  
Total Inhibition ◽  
Purification And Properties

Aim: To characterize the enzyme phytase produced by phytase-active Candida melibiosica 2491 for subsecuent use in feed industry. Methods: C. melibiosica 2491 had been selected among 118 strains as the most productive strain of phytase. In present study, the enzyme was first purified through electrophoresis grade in four steps: precipitation with organic solvent, ultrafiltration, gel chromatography and Denaturing gel electrophoresis (SDS–PAGE). Results: Higher levels of purification were obtained using ethanol. The gel chromatography showed an elution maximum at 11-12 fractions that characterize the corresponding one as high-molecular weight phytase. The purification level was found to be 19.5 folds with specific enzyme activity of 2.75 U/mg protein and yield – 19.64 %. Furthermore, the molecular weight of purified phytase was estimated to 35.9 кDa, with optimum of pH – at 4.5 and optimum of temperature at 55 °C. Maximum phytase activity in case of whole cells was found at 50 оС, which was less than using the purified enzyme. It was activated through 5 mM of Ba2+, 10 mM of Mn2+ and K+ ions. Total inhibition effect was achieved from Fe3+, Hg2+ and Zn2+. Copper ions (Cu2+) in concentrations at 5 mM conducted to partial inhibition effect, but at 10 mM the phytase activity was equal to zero. Low inhibition effect was determined in case of cobalt ions (Co2+) at concentrations of 10 mM. The phytase displayed broad sub­strate specificity and the Km for phytate was estimated to be 0.21 mM under the experimental conditions, while Vmax – 19.9 µМ/ml. Conclusion: Although the phytase produced by C. melibiosica 2491 is a promising enzyme to be used successfully in feed production, more investigations are needed to ensure its advantages.

A new software of calculating the pH values of coastal seawater: Considering the effects of low molecular weight organic acids

2019 ◽  
Vol 211 ◽  
pp. 108-116 ◽  
Author(s):  
Li-Na Lyu ◽  
Daoming Lu ◽  
Chengjun Sun ◽  
Haibing Ding ◽  
Liang-Min Yu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Acids ◽  
Low Molecular Weight ◽  
Coastal Seawater ◽  
Ph Values

scholarly journals Deoxyribonucleic acid polymerases of Euglena gracilis. Purification and properties of two distinct deoxyribonucleic acid polymerases of high molecular weight

1975 ◽  
Vol 151 (2) ◽  
pp. 227-238 ◽  
Author(s):  
A G McLennan ◽  
H M Keir
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Euglena Gracilis ◽  
Deoxyribonucleic Acid ◽  
Deae Cellulose ◽  
Low Molecular Weight ◽  
Optimum Conditions ◽  
Electrophoretic Mobilities ◽  
Substrate Activation ◽  
Purification And Properties

Two DNA polymerases of high molecular weight, pol A (mol.wt. 190 000) and pol B (mol.wt. 240 ooo), have been purified 6300-fold and 1600-fold respectively from an extramitochondrial supernatant of a bleached strain of Euglena gracilis. They have very similar requirements when assayed with an ‘activated’-DNA primer-template [the optimum conditions of pH and ionic (K+ and Mn2+) composition being 7.2, 25 mM and 0.2 mM respectively]. 0.2 mM-Mn2+ was about 1.5-2-fold as effective as 2 mM-Mg2+, owing to substrate activation by deoxyribonucleoside 5′-triphosphates in the presence of Mn2+. Km values for the triphosphates in the absence of activation were about 10(-6)M with Mn2+ and 8 × 10(-6) M with Mg2+ for both enzymes. They were inhibited to the same extent by N-ethylmaleimide, novobiocin and o-phenanthroline, but differed in their chromatographic behaviour on DEAE-cellulose and in their electrophoretic mobilities on polyacrylamide gel. No evidence was found for the existence in these cells of a DNA polymerase of low molecular weight, but there were indications that a third enzyme of high molecular weight might exist.

ESR study of copper(II) retention by entire cell, cells walls, and protoplasts of Saccharomyces cerevisiae

1987 ◽  
Vol 33 (9) ◽  
pp. 777-782 ◽  
Author(s):  
Jean Claude Kihn ◽  
Michèle M. Mestdagh ◽  
Paul G. Rouxhet
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Energy Source ◽  
Plasma Membrane ◽  
Binding Sites ◽  
Cell Walls ◽  
Outer Face ◽  
Whole Cells ◽  
Entire Cell ◽  
Acidic Conditions ◽  
Isolated Cell

Copper retention by whole cells, protoplasts, and isolated cell walls of Saccharomyces cerevisiae was investigated in the absence of any energy source in the medium. The cell walls accounted only for a small fraction of the cation retention by whole cells. ESR results showed that copper was not bound only at the outer face of the plasma membrane, but it was also distributed in the plasma membrane and (or) in the cytoplasm. ESR studies also showed that, in all three systems, copper was chelated by peptides or proteins. The binding sites were formed by an amide and a strongly complexing ligand such as an amine. Their configuration depended upon pH: in slightly acidic conditions, copper was bound by the oxygen of the amide; at basic pH, NHCO became deprotonated and the negatively charged nitrogen bound to the metal.

Purification and properties of human low molecular weight kininogen

1982 ◽  
Vol 706 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Werner Müller-Esterl ◽  
Magdalene Vohle-Timmermann ◽  
Barbara Boos ◽  
Brigitte Dittman
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Purification And Properties

scholarly journals Products of Metabolism and Processing of Lactic Acid Bacteria as Functional Ingredients

2018 ◽  
Vol 1 (1) ◽  
pp. 47 ◽  
Author(s):  
Antonina Ivanovna Kapustian ◽  
Natalia Cherno ◽  
Alexei Kovalenko ◽  
Kristina Naumenko ◽  
Igor Kushnir
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Organic Acids ◽  
Cell Walls ◽  
Degradation Products ◽  
Lactobacillus Delbrueckii ◽  
Low Molecular Weight ◽  
Gel Chromatography

Lactic acid bacteria (LAB) and bifidobacteria (BB) are unique substances that have a lot of biological and physiological effects. Structural components of LAB and BB – peptidoglycans, compounds of the muramylpeptide series, teichoic acids – have powerful immunological properties. Metabolites of LAB and BB – organic acids, hydrogen peroxide, bacteriocins, etc. – provide antagonistic activity, have an indirect impact on the immune system, reducing the antigenic load caused by pathogenic microorganisms. The expediency of peptidoglycans degradation of LAB and BB cell walls is substantiated. Low molecular weight products of the degradation can easily be absorbed and enter into biochemical processes, accelerating the expected functional-physiological effect. To obtain low-molecular products of peptidoglycans degradation, a combination of LAB and BB was used. The combination of LAB and BB is the sum of the test cultures of Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Bifidobacterium bifidum, Lactococcus cremoris, Streptococcus termophilus. Destruction of peptidoglycans of bacterial cell walls was carried out using a combination of disintegrating factors. The efficiency of destruction was determined by the accumulation of low molecular weight peptides (with molecular weight up to 1500 Da), amino acids and soluble protein in the disintegrate. It has been established that the highest accumulation of low molecular weight degradation products occurs when using autolysis followed by enzymatic hydrolysis during 180 min with the ratio of the enzyme : substrate 1 : 100. At the same time ≈ 53% of protein substances pass from insoluble to soluble state. The molecular weight of the obtained products is determined by the gel chromatography method. The qualitative and quantitative content of organic acids, amino acids and vitamins of group В in the hydrolysis products composition was investigated. It was shown that the obtained product possesses high biological effect in the experiment on animals.

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