Properties of chitin synthase from mucoraceous hosts of a mycoparasite

1985 ◽  
Vol 31 (1) ◽  
pp. 6-12 ◽  
Author(s):  
M. S. Manocha ◽  
A. Begum
Keyword(s):  
Enzyme Activity ◽  
Enzyme Preparation ◽  
Rapid Decrease ◽  
Chitin Synthase ◽  
Enzyme Preparations ◽  
Protease Enzyme ◽  
Choanephora Cucurbitarum ◽  
Endogenous Proteases ◽  
And Storage ◽  
Narrow Concentration Range

Crude chitin synthase extracted from young (24 h) hyphae of Choanephora cucurbitarum and Phascolomyces articulosus, susceptible and resistant hosts, respectively, to the mycoparasite, Piptocephalis virginiana, was identified and characterized by measuring the incorporation of the substrate [14C]UDP – N-acetylglucosamine into chitin. The enzyme activity was mainly associated with the mixed membrane fraction. Properties of the enzyme preparation such as activation with proteases, N-acetylglucosamine, magnesium, inhibition with polyoxin D, Vmax, apparent Km value for UDP – N-acetyl-D-glucosamine (UDP-GlcNAc), and response to pH were examined. Enzyme activity from both fungi displayed basically the same features as the corresponding enzymes reported from other mucoraceous fungi. However, the two enzyme preparations (from P. articulosus and C. cucurbitarum) differed from each other in their response to various proteases and storage at 4 °C. Enzyme preparation from P. articulosus was activated by all proteases, whereas the C. cucurbitarum preparation was activated by acid protease, slightly activated by trypsin over a narrow concentration range, and was inhibited by neutral protease. Enzyme preparation from C. cucurbitarum showed a rapid decrease in activity within the first 5 h of storage at 4 °C and also exhibited relatively higher activity of endogenous proteases than that from P. articulosus.

Synthesis of β-glucan by cell-free extracts of Aureobasidium pullulans

1987 ◽  
Vol 33 (2) ◽  
pp. 123-127 ◽  
Author(s):  
Malcolm A. J. Finkelman ◽  
Alex Vardanis
Keyword(s):  
Enzyme Activity ◽  
Acetic Acid ◽  
Bovine Serum Albumin ◽  
Aureobasidium Pullulans ◽  
Enzyme Preparation ◽  
Glucanase Activity ◽  
Free System ◽  
Enzyme Preparations ◽  
Partial Activation ◽  
A Cell

A cell-free system catalysing the synthesis of β-glucan from uridine-diphosphoglucose was prepared from Aureobasidium pullulans. The activity was stable in the presence of 1 M sucrose and 10 mM MgSO4. The polymer produced was insoluble in H2O or acetic acid (0.5 M) and soluble in NaOH (0.5 M). Several enzyme preparations containing β-glucanase activity degraded the polymer to various extents. Synthesis of the polymer was enhanced by the presence of cellobiose and bovine serum albumin, but not by NaF or ATP. A Lineweaver–Burke plot of enzyme activity versus substrate concentration revealed biphasic kinetics. The enzyme preparation was subject to partial activation by trypsin and chymotrypsin.

scholarly journals Effect of Methyl Jasmonate, Cytokinin, and Lavender Oil on Antioxidant Enzyme System of Apricot Fruit (Prunus armeniaca L.)

2021 ◽  
Vol 13 (15) ◽  
pp. 8565
Author(s):  
Seyda Cavusoglu ◽  
Nurettin Yilmaz ◽  
Firat Islek ◽  
Onur Tekin ◽  
Halil Ibrahim Sagbas ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Methyl Jasmonate ◽  
Prunus Armeniaca ◽  
Lavender Oil ◽  
Defense Systems ◽  
Antioxidant Enzyme System ◽  
Prunus Armeniaca L ◽  
Antioxidant Defense Systems ◽  
And Storage

Various treatments are carried out in order to extend both the shelf life and storage life of fresh fruit and vegetables after harvest and among them non-toxic for humans, environmentally and economically friendly alternative treatments are gained more importance. In the current study, methyl jasmonate (MeJA), cytokinin, and lavender oil which are eco-friendly and safe for human health were applied on apricot fruit. The treated fruit were stored at 0 °C and 90–95% relative humidity for 25 days and catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX) enzyme activities and lipid peroxidation of apricots after treatments were studied. According to the findings obtained from the study, it was observed that 5 ppm cytokinin and 1000 ppm lavender oil treatments of apricot fruit gave better APX and CAT enzyme activity, respectively. In addition, better SOD enzyme activity in fruit was obtained with MeJA+lavender oil treatments. As a result, it can be emphasized that the product quality of apricot fruit is preserved as both the eco-friendly application of MeJA, cytokinin, and lavender oil separately from each other and the treatment of combinations between these compounds activate the enzymatic antioxidant defense systems of apricot fruit after harvest.

scholarly journals Purification and subunit structure of argininosuccinate lyase from Chlamydomonas reinhardi

1977 ◽  
Vol 167 (1) ◽  
pp. 71-75 ◽  
Author(s):  
R F Matagne ◽  
J P Schlösser
Keyword(s):  
Enzyme Activity ◽  
Crude Extract ◽  
Enzyme Preparation ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Activity Analysis ◽  
Disc Electrophoresis ◽  
Subunit Structure ◽  
Argininosuccinate Lyase

Argininosuccinate lyase (EC 4.3.2.1) was purified by (NH4)2SO4 fractionation, chromatography on DEAE-cellulose and gel filtration on Sephadex G-200. The final enzyme preparation was purified 46-fold compared with the crude extract. Electrophoresis of this preparation revealed three bands, the major one having the enzyme activity. Analysis of the enzyme by gel filtration and by disc electrophoresis (in two different concentrations of acrylamide) gave mol.wts. of 200000 (+/- 15000) and 190000 (+/- 20000) respectively. Treatment with sodium dodecyl sulphate and mercaptoethanol dissociated the enzyme into subunits of mol.wt. 39000 (+/-2000). The results are indicative of the multimeric structure of the enzyme, which is composed of five (perhaps four or six) identical subunits.

scholarly journals Interaction of soluble glucosyl- and mannosyl-transferase enzyme activities in the synthesis of a glucomannan

1972 ◽  
Vol 129 (3) ◽  
pp. 645-655 ◽  
Author(s):  
J. S. Heller ◽  
C. L. Villemez
Keyword(s):  
Enzyme Activity ◽  
Enzyme Activities ◽  
Enzyme Preparation ◽  
The Other ◽  
Acceptor Molecule ◽  
Soluble Enzyme ◽  
Phaseolus Aureus ◽  
Polymeric Product ◽  
Sugar Nucleotide ◽  
Solubilized Enzyme

A neutral-detergent-solubilized-enzyme preparation derived from Phaseolus aureus hypocotyls contains two types of glycosyltransferase activity. One, mannosyltransferase enzyme activity, utilizes GDP-α-d-mannose as the sugar nucleotide substrate. The other, glucosyltransferase enzyme activity, utilizes GDP-α-d-glucose as the sugar nucleotide substrate. The soluble enzyme preparation catalyses the formation of what appears to be a homopolysaccharide when either sugar nucleotide is the only substrate present. A β-(1→4)-linked mannan is the only polymeric product when only GDP-α-d-mannose is added. A β-(1→4)-linked glucan is the only polymeric product when only GDP-α-d-glucose is added. In the presence of both sugar nucleotides, however, a β-(1→4)-linked glucomannan is formed. There are indications that endogenous sugar donors may be present in the enzyme preparation. There appear to be only two glycosyltransferases in the enzyme preparation, each catalysing the transfer of a different sugar to the same type of acceptor molecule. The glucosyltransferase requires the continual production of mannose-containing acceptor molecules for maintenance of enzyme activity, and is thereby dependent upon the activity of the mannosyltransferase. The mannosyltransferase, on the other hand, does not require the continual production of glucose-containing acceptors for maintenance of enzyme activity, but is severely inhibited by GDP-α-P-glucose. These properties promote the synthesis of β-(1→4)-linked glucomannan rather than β-(1→4)-linked glucan plus β-(1→4)-linked mannan when both sugar nucleotide substrates are present.

scholarly journals ANTIOXIDANT ENZYME ACTIVITY AND FRESH-CUT ARRACACHA QUALITY

2015 ◽  
Vol 39 (3) ◽  
pp. 276-282
Author(s):  
Hêmina Carla Vilela ◽  
Patrícia de Fátima Pereira Goulart ◽  
Kamila Rezende Dázio de Souza ◽  
Ana Carolina Vilas Boas ◽  
Jane Silva Roda ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Antioxidant Enzymes ◽  
Nutritional Value ◽  
Storage Period ◽  
Antioxidant Enzyme Activity ◽  
Useful Life ◽  
Fresh Cut ◽  
Processing Techniques ◽  
And Storage ◽  
Microbiological Aspects

The arracacha is an alternative of fresh-cut product; however it can be easily degraded after the processing techniques. The objective of this work was to evaluate the useful life of fresh-cut arracacha submitted to two types of cuts and storage, as well as to evaluate the activity of antioxidant enzymes. The roots were selected, sanitized and submitted to two cut types: cubed and grated. Then they were evaluated at 3 times: 0, 3 and 7 days. The cutting in cubes provided higher quality and lower SOD, CAT and APX activity. However, the grated product presented higher PG activity and lower PPO activity. The microbiological safety and the nutritional value were maintained in both cuts during the whole storage period. The useful life, regarding the physicochemical, nutritional and microbiological aspects, can be established at 7 days under refrigeration for fresh-cut arracacha.

Digestive enzyme and gut surfactant activity of detritivorous gizzard shad (Dorosoma cepedianum)

2000 ◽  
Vol 57 (6) ◽  
pp. 1113-1119 ◽  
Author(s):  
James C Smoot ◽  
Robert H Findlay
Keyword(s):  
Enzyme Activity ◽  
Protease Activity ◽  
Feeding Strategy ◽  
Digestive Enzyme ◽  
Artificial Substrates ◽  
Gizzard Shad ◽  
Dorosoma Cepedianum ◽  
Digestive Physiology ◽  
Protease Enzyme ◽  
Surfactant Activity

Measuring digestive enzyme and surfactant activities tested specialization of gizzard shad (Dorosoma cepedianum) digestive physiology to a detritivorous feeding strategy. Digestive enzyme activity was measured in adult and larval gizzard shad using fluorescently labeled artificial substrates. Surfactant activity in gizzard shad was measured by comparing gut juice drop diameters over a range of dilutions. Enzyme activity in the ceca region of adult gizzard shad was high for esterase, beta-glucosidase, lipase, and protease. Enzyme activity was lower in posterior intestine sections than in anterior intestine sections, although protease activity remained high for the greatest distance in the intestine. Micelles were detected in adult gizzard shad gut juice, and surfactant activity was greatest in the ceca region. Larval gizzard shad protease activity was similar to that of adult fish, and surfactants were below their critical micelle concentration. Gizzard shad coupled digestive physiology with gut anatomy to obtain nutrients from detritus, and these adaptations may explain elevated growth rates observed in these fish when they are planktivorous.

scholarly journals Effect of enzyme preparation Ceramics 6XMG on indicators of oat malt quality

2018 ◽  
Vol 80 (3) ◽  
pp. 128-133
Author(s):  
G. V. Agafonov ◽  
A. E. Chusova ◽  
A. V. Zelenkova ◽  
V. E. Plotnikov
Keyword(s):  
Enzyme Preparation ◽  
Colorimetric Method ◽  
Biologically Active ◽  
Complex Action ◽  
Drying Time ◽  
Pronounced Increase ◽  
Enzyme Preparations ◽  
Organoleptic Characteristics ◽  
Object Of Study

One of the effective ways to increase the malt capacity of existing plants is the use of complex enzyme preparations. The enzyme preparation of complex action, penetrating into the grain during soaking or germination, affect its powdery body, contributing to the loosening of the cell membranes and the endosperm itself, thereby accelerating the process of malting. A purpose of researches is development of technology of fermented oat malt with the use of enzyme drug Ceramics 6ХМG. This enzyme preparation with complex action, has ?-amylase, protease, ?-glucanase, pentosanase, cellulose activities. As the object of study was taken oats Kozyr’ variety. Amylolytic ability of malt was determined by colorimetric method, proteolytic-refractometric method (according to Petrov). It was established that as a result of the use of Ceremix 6XMG in an amount of 0.1–0.5 kg per ton of grain, a more pronounced increase in amylolytic and proteolytic ability compared to the control (without the use of an enzyme preparation) occurs at a dosage of 0.5 kg per ton of grain. It is impractical to introduce Ceremix 6HMG in the amount of 0.5 kg per ton of grain, because the enzymatic activity of oat malt is only 6.4–6.6% higher than that of malt treated with an enzyme preparation in the amount of 0.3 kg per ton of grain. It was found that the use of the enzyme preparation Ceremix 6HMG allows to improve the quality of oat malt by improving organoleptic characteristics, increasing the mass fraction of extractives, as well as to intensify the process by reducing the drying time by 10-12 hours, which is important for the preservation of biologically active substances and energy resources.

scholarly journals Pre-fermentative treatment of a model wine with aim to serve as a functional food with decreased alcohol content

2017 ◽  
Vol 63 (01) ◽  
pp. 47-53
Author(s):  
Irina Mladenoska ◽  
Verica Petkova ◽  
Tatjana Kadifkova Panovska
Keyword(s):  
Enzyme Activity ◽  
Gluconic Acid ◽  
Functional Food ◽  
Ph Value ◽  
Enzymatic Reaction ◽  
Alginate Beads ◽  
High Concentration ◽  
Ph Optimum ◽  
Enzyme Preparations ◽  
Initial Ph

The effect of substrate concentration on the enzyme activity in the reaction of glucose conversion into gluconic acid was investigated by using three different enzyme preparations in media with two different glucose concentrations. The media were simulating the conditions in the must, thus named as minimal model must, and were composed form combination of several organic acids and glucose. Those media were having initial pH of 3.5 that is a very unfavorable for glucose oxidase activity having a pH optimum at the pH value of 5.5. Among the three preparations used, the bakery additive, Alphamalt Gloxy 5080, was the most active in the medium with glucose concentration of 10 g/L, showing conversion of more than 70% for the period of 24 h, while the same enzyme preparation in the medium with 100 g/L glucose converted only about 7% of glucose. The pH value of the medium at the beginning and at the end of the enzymatic reaction was a good indicator of the enzyme activity. It seems that for the conversion of glucose in higher concentration, enzymatic preparation in high concentration should also be used. The preliminary attempt of immobilization of two preparations of glucose oxidases in alginate beads was also performed and a successful immobilization procedure for utilization in food industry was preliminarily developed. Keywords: glucose oxidases, enzymatic pretreatment, glucose, gluconic acid, model wine, functional food

THE HETEROGENEITY OF PANCREATIC DEOXYRIBONUCLEASE

1962 ◽  
Vol 40 (2) ◽  
pp. 165-175 ◽  
Author(s):  
G. C. Becking ◽  
R. O. Hurst
Keyword(s):  
Enzyme Activity ◽  
Ionic Strength ◽  
Enzyme Preparation ◽  
Deoxyribonucleic Acid ◽  
Paper Electrophoresis ◽  
Relative Activity ◽  
Enzyme Concentration ◽  
Uranyl Acetate ◽  
Ph Optimum

The action of crystalline pancreatic deoxyribonuclease on sodium oligonucleotides in the presence of manganous ions has been studied and a pH optimum of 6.6 observed. Inhibition of the enzyme activity by increased ionic strength of the digest occurred. The liberation of products soluble in uranyl acetate – trichloroacetate was found to vary with enzyme concentration and the relative activity of the enzyme on oligonucleotides was best determined by a logarithm-plot method. The activity of the enzyme towards deoxyribonucleic acid or sodium oligonucleotides as substrate was not affected by treatment with acetone. Evidence of heterogeneity in the crystalline enzyme preparation was obtained using paper electrophoresis and chromatography on carboxymethylcellulose. Two fractions were separated that showed different ratios of activity towards the two substrates employed.

Biochemical and in vitro assessment of six enzyme preparations as potential feed additives

2000 ◽  
Vol 2000 ◽  
pp. 54-54 ◽  
Author(s):  
D. Colombatto ◽  
F. L. Mould ◽  
M. K. Bhat ◽  
E. Owen
Keyword(s):  
Enzyme Preparation ◽  
Rumen Fluid ◽  
Enzymatic Activities ◽  
Feed Additives ◽  
Cell Wall Degrading Enzymes ◽  
Enzyme Preparations ◽  
Factors Affecting ◽  
Considerable Research ◽  
In Vitro Assessment

Considerable research efforts have been directed towards the use of cell wall degrading enzymes as feed additives. However, the factors affecting the response to a certain enzyme preparation are not well understood. A better knowledge of the enzymatic activities present in the preparations and their interaction with a substrate in presence of rumen fluid is needed. The objectives of this study were to characterise the main enzymatic activities of six enzyme preparations and to evaluate them in the presence of rumen fluid, using thein vitroReading Pressure Technique (RPT).

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