scholarly journals Exo-β-glucanases in yeast

1968 ◽  
Vol 109 (3) ◽  
pp. 347-360 ◽  
Author(s):  
Ahmed T. H. Abd-El-Al ◽  
H. J. Phaff
Keyword(s):  
Specific Activity ◽  
Culture Fluid ◽  
Competitive Inhibitor ◽  
Cell Extract ◽  
Baker’S Yeast ◽  
Maximal Velocity ◽  
Baker's Yeast ◽  
Molecular Weights ◽  
Hansenula Anomala ◽  
Single Enzyme

1. A number of yeast species were examined for the presence of β-glucanases. Extracts obtained by cell disruption of Saccharomyces cerevisiae, Fabospora fragilis and Hansenula anomala hydrolysed laminarin and pustulan with the production of glucose. Enzymic activities were also detected in the culture fluids of F. fragilis and H. anomala grown aerobically in buffered mineral medium with glucose as the carbon source. 2. F. fragilis and H. anomala possessed approximately sevenfold higher β-(1→3)-glucanase activity than S. cerevisiae. 3. Intracellular exo-β-glucanase from baker's yeast was purified 344-fold from the dialysed cell extract. 4. Exo-β-glucanase from F. fragilis was purified 114-fold from the dialysed culture fluid and 423-fold from the dialysed intracellular extract. The purified extracellular and intracellular enzymes had similar properties and essentially the same specific activity, 79 enzyme units/mg. of protein. 5. Extracellular exo-β-glucanase of H. anomala was purified 600-fold. 6. The optimum pH of the enzymes from F. fragilis, S. cerevisiae and H. anomala was 5·5 in each case. Chromatographic evidence indicated that the three enzymes remove glucosyl units sequentially from laminarin as well as pustulan. 7. The ratio of activities towards laminarin and pustulan remained constant during purification of the exo-β-glucanase obtained from the three species, suggesting a single enzyme. Additional evidence for its unienzymic nature are: (i) the two activities were destroyed at exactly the same rate on heating of the purified enzyme from F. fragilis at three different temperatures; (ii) the competitive inhibitor glucono-δ-lactone gave the same value of Ki when tested with either substrate; (iii) quantitative application of the ‘mixed-substrate’ method with the purified enzyme of S. cerevisiae gave data that were in excellent agreement with those calculated on the assumption of a single enzyme. 8. The purified exo-β-glucanases of the different species of yeast had different kinetic constants. The ratios of maximal velocities and Km values with laminarin and pustulan differed markedly. Comparison of Vmax. and Km values suggests that the rapid release of spores from asci in F. fragilis might be explained in terms of an enzyme with higher maximal velocity and higher affinity to the ascus wall than that present in baker's yeast. 9. The estimated molecular weights for exo-β-glucanases from F. fragilis, S. cerevisiae and H. anomala were 22000, 40000 and 30000 respectively.

scholarly journals The purification and some properties of 3-hydroxy-3-methylglutaryl-coenzyme A synthase from baker's yeast

1972 ◽  
Vol 126 (1) ◽  
pp. 27-34 ◽  
Author(s):  
B. Middleton ◽  
P. K. Tubbs
Keyword(s):  
Time Course ◽  
Specific Activity ◽  
Reaction Pathway ◽  
Gel Filtration ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Complete Protection ◽  
Acetyl Coa ◽  
Molecular Weights ◽  
Enzyme Intermediate

1. A purification of 3-hydroxy-3-methylglutaryl-CoA synthase from baker's yeast is described. This yields a preparation of average specific activity 2.1 units (μmol/min)/mg in which contamination by acetoacetyl-CoA thiolase is less than 0.2%. 2. The molecular weights of 3-hydroxy-3-methylglutaryl-CoA synthase and acetoacetyl-CoA thiolase from baker's yeast were determined by gel filtration on Sephadex G-200. The values obtained were 130000 and 190000 respectively. 3. 3-Hydroxy-3-methylglutaryl-CoA synthase is susceptible to irreversible inhibition by a wide variety of alkylating and acylating agents. The time-course of inhibition of the enzyme by some of these, including the active-site-directed inhibitor bromoacetyl-CoA, was studied in the presence and absence of substrates, products and product analogues. Acetyl-CoA, even when present at concentrations as low as 5μm, gives almost complete protection. Other acyl-CoA derivatives give some protection, but only at concentrations 10–30-fold higher. 4. These results are discussed with reference to an ordered reaction pathway in which acetyl-CoA reacts to give a covalent acetyl-enzyme intermediate.

scholarly journals Some properties of an alcohol dehydrogenase partially purified from baker's yeast grown without added zinc

1976 ◽  
Vol 153 (2) ◽  
pp. 309-319 ◽  
Author(s):  
C J Dickenson ◽  
F M Dickinson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alcohol Dehydrogenase ◽  
Maximum Rate ◽  
Ethanol Oxidation ◽  
Competitive Inhibitor ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Kinetic Characteristics ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mechanism Of Catalysis

Alcohol dehydrogenase was partially purified from yeast (Saccharomyces cerevisiae) grown in the presence of 20 μM-MnSO4 without added Zn2+ and from yeast grown in the presence of 1.8 μM-MnSO4. The enzyme from yeast grown with added Zn2+ has the same properties as the crystalline enzyme from commercial supplies of baker's yeast. The enzyme from yeast grown without added An2+ has quite different properties. It has a mol.wt. in the region of 72000 and an S 20 w of 5.8S. The values can be compared with a mol.wt. of 141000 and an S 20 w of 7.6S for the crystalline enzyme. ADP-ribose, a common impurity in commercial samples of NAD+, is a potent competitive inhibitor of the new enzyme (K1 = 0.5 μM), but is not so for the crystalline enzyme. The observed maximum rate of ethanol oxidation at pH 7.05 and 25 degrees C was decreased 12-fold by the presence of 0.06 mol of inhibitor/mol of NAD+ when using the enzyme from Zn2+-deficient yeast, but with crystalline enzyme the maximum rate was essentially unchanged by this concentration of inhibitor. The kinetic characteristics for the two enzymes with ethanol, butan-1-ol, acetaldehyde and butyraldehyde as substrates are markedly different. These kinetic differences are discussed in relation to the mechanism of catalysis for the enzyme from Zn2+-deficient yeast.

scholarly journals ISOLATION OF HEXOKINASE FROM BAKER'S YEAST

1946 ◽  
Vol 29 (6) ◽  
pp. 379-391 ◽  
Author(s):  
Louis Berger ◽  
Milton W. Slein ◽  
Sidney P. Colowick ◽  
Carl F. Cori
Keyword(s):  
Specific Activity ◽  
Proteolytic Enzymes ◽  
Protective Action ◽  
Fold Increase ◽  
Inhibitory Effect ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Thiol Compounds ◽  
Protective Proteins ◽  
Yeast Hexokinase

1. A method is described for the isolation of hexokinase from baker's yeast. The method is based mainly on fractionation with alcohol and results See PDF for Structure in a 30-fold increase in specific activity. The final product could be crystallized from ammonium sulfate without change in specific activity. 2. The enzyme catalyzes a transfer of phosphate from adenosinetriphosphate to glucose, fructose, or mannose, the relative rates with these three sugars being 1:1.4:0.3. 3. With glucose as substrate, the turnover number for the crystalline enzyme is 13,000 moles of substrate per 105 gm. of protein per minute at 30° and pH 7.5. The temperature coefficient (Q10°) between 0 and 30° is 1.9. 4. Magnesium ions are necessary for the activity, the dissociation constant for the Mg++ -protein complex being 2.6 x 10–3. Fluoride in concentrations as high as 0.125 M has no inhibitory effect on the enzyme when the Mg++ and orthophosphate concentrations are 6.5 x 10–3 M and 1 x 10–3 M, respectively. 5. The crystalline enzyme shows a loss in activity when highly diluted. This loss in activity can be prevented by diluting in the presence of small amounts of other proteins. Of the various protective proteins tested, insulin was the most effective, providing complete protection in a concentration of 6 micrograms per cc.; with serum albumin, a concentration of 60 micrograms per cc. was necessary. Thiol compounds (cysteine, glutathione) exerted no protective action. 6. The inactivation of the crystalline enzyme on incubation with trypsin can be prevented to a marked degree by the presence of glucose. The instability of crude preparations of yeast hexokinase may be attributed to the presence of proteolytic enzymes, since glucose or fructose has a remarkable protective effect on such preparations.

Soluble Thrombomodulin Purified from Human Urine Exhibits a Potent Anticoagulant Effect In Vitro and In Vivo

1995 ◽  
Vol 73 (05) ◽  
pp. 805-811 ◽  
Author(s):  
Yasuo Takahashi ◽  
Yoshitaka Hosaka ◽  
Hiromi Niina ◽  
Katsuaki Nagasawa ◽  
Masaaki Naotsuka ◽  
...  
Keyword(s):  
Human Urine ◽  
Specific Activity ◽  
Anticoagulant Activity ◽  
Rabbit Lung ◽  
Soluble Thrombomodulin ◽  
Molecular Weights ◽  
Dose Dependent Fashion ◽  
Dose Dependent

SummaryWe examined the anticoagulant activity of two major molecules of soluble thrombomodulin purified from human urine. The apparent molecular weights of these urinary thrombomodulins (UTMs) were 72,000 and 79,000, respectively. Both UTMs showed more potent cofactor activity for protein C activation [specific activity >5,000 thrombomodulin units (TMU)/mg] than human placental thrombomodulin (2,180 TMU/mg) and rabbit lung thrombomodulin (1,980 TMU/mg). The UTMs prolonged thrombin-induced fibrinogen clotting time (>1 TMU/ml), APTT (>5 TMU/ml), TT (>5 TMU/ml) and PT (>40 TMU/ml) in a dose-dependent fashion. These effects appeared in the concentration range of soluble thrombomodulins present in human plasma and urine. In the rat DIC model induced by thromboplastin, administration of UTMs by infusion (300-3,000 TMU/kg) restored the hematological abnormalities derived from DIC in a dose-dependent fashion. These results demonstrate that UTMs exhibit potent anticoagulant and antithrombotic activities, and could play a physiologically important role in microcirculation.

Low Molecular Weight Trypsin-Plasmin Inhibitors Isolated from Papain Treated Urinary Trypsin Inhibitor

1982 ◽  
Vol 47 (01) ◽  
pp. 014-018 ◽  
Author(s):  
H Sumi ◽  
N Toki ◽  
S Takasugi ◽  
S Maehara ◽  
M Maruyama ◽  
...  
Keyword(s):  
Trypsin Inhibitor ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Chromatography ◽  
Urinary Trypsin Inhibitor ◽  
Plasmin Activity ◽  
Molecular Weights ◽  
Plasmin Inhibitors

SummaryPapain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, and UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotrypsin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10-7 - 2.12 X 10-6 M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors to plasmin was thought to be different from that to trypsin or chymotrypsin.

COD REDUCTION OF BAKER'S YEAST WASTEWATER USING BATCH ELECTROCOAGULATION

2014 ◽  
Vol 13 (12) ◽  
pp. 3153-3160 ◽  
Author(s):  
Zakaria Al-Qodah ◽  
Mohammad Al-Shannag ◽  
Kholoud Alananbeh ◽  
Nahla Bouqellah ◽  
Eman Assirey ◽  
...  
Keyword(s):  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Cod Reduction ◽  
Yeast Wastewater

The use of β-glucan extracted from baker’s yeast (Saccharomyces cerevisiae) to increase non-specific immune system and resistence of tilapia (Oreochromis niloticus) to Aeromonas hydrophila

2013 ◽  
pp. 92
Author(s):  
Ida N Jamal ◽  
Reiny A Tumbol ◽  
Remy E.P Mangindaan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Immune System ◽  
Aeromonas Hydrophila ◽  
Phagocytic Activity ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Yeast Saccharomyces Cerevisiae ◽  
Randomized Design ◽  
The Difference ◽  
Motile Aeromonas Septicaemia

Motile Aeromonas Septicaemia disease (MAS) attacking tilapia has increased in recent years as a consequence of intensive aquaculture activities, which led to losses in aquaculture industry. The agent causing MAS disease is Aeromonas hydrophila. The disease can be controlled with the β-glucan. As immunostimulants, β-glucans can also increase resistance in farmed tilapia. Studies on the use of β-glucan extracted from baker's yeast Saccharomyces cerevisiae was intended to evaluate the non-specific immune system of tilapia that were challenged with Aeromonas hydrophila. The method used was an experimental method with a completely randomized design consisting of four treatments with three replicats. The dose of β-glucan used as treatments were 0 mg.kg-1 fish (Control), 5 mg.kg-1 fish (B), 10 mg.kg-1 fish (C) and 20 mg.kg-1 fish (D), each treatment as injected three times at intervals of 3 days, the injection volume of 0.5 ml/fish for nine days and resistance surveillance for seven days. The results showed that the difference in the amount of β-glucan and the frequency of the injected real influence on total leukocytes, phagocytic activity and resistance. Total leukocytes, phagocytic activity and resistance to treatment was best achieved by the administration of C a dose of  10 mg.kg-1 of the fish© Penyakit Motil Aeromonas Septicaemia (MAS) yang menyerang ikan nila mengalami peningkatan selama beberapa tahun terakhir sebagai konsekuensi dari kegiatan akuakultur intensif, yang menyebabkan kerugian dalam industri budidaya. Agen utama penyebab penyakit MAS adalah Aeromonas hydrophila. Untuk mengendalikan penyakit tersebut dapat dilakukan dengan pemberian β-glukan. Sebagai imunostimulan, β-glukan juga dapat  meningkatkan resistensi pada ikan nila yang dibudidayakan. Pengkajian mengenai pemanfaatan β-glukan yang diekstrak dari ragi roti Saccharomyces cerevisiae dimaksudkan untuk menguji sistem imun non spesifik ikan nila yang diuji tantang dengan bakteri Aeromonas hydrophila. Metode yang digunakan yaitu metode eksperimen dengan rancangan acak lengkap yang terdiri dari empat perlakuan dan tiga ulangan. Dosis β-glukan  yang digunakan sebagai perlakuan sebesar 0 mg.kg-1 ikan (Kontrol), 5 mg.kg-1 ikan (B), 10 mg.kg-1 ikan (C) dan 20 mg.kg-1 ikan (D), masing-masing perlakuan diinjeksi sebanyak 3 kali dengan interval waktu 3 hari selama 9 hari, volume injeksi 0,5 mL/ekor ikan dan pengamatan resistensi selama tujuh hari. Hasil penelitian menunjukkan perbedaan jumlah β-glukan dan frekuensi pemberian yang diinjeksikan memberikan pengaruh nyata terhadap total leukosit, aktivitas fagositosis dan resistensi. Total leukosit, aktivitas fagositosis dan resistensi terbaik dicapai pada perlakuan C dengan dosis 10 mg.kg-1 ikan©

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