Role of cinnamoyl esterase activities from enzyme preparations on the formation of volatile phenols during winemaking

1993 ◽  
Vol 41 (11) ◽  
pp. 2092-2096 ◽  
Author(s):  
Isabelle. Dugelay ◽  
Ziya. Gunata ◽  
Jean Claude. Sapis ◽  
Raymond. Baumes ◽  
Claude. Bayonove
Keyword(s):  
Volatile Phenols ◽  
Enzyme Preparations ◽  
Cinnamoyl Esterase ◽  
Esterase Activities

Dissociation of FAD from the NAD(P)H-Nitrate Reductase Complex from Ankistrodesmus braunii and Role of Flavin in Catalysis

1982 ◽  
Vol 37 (1-2) ◽  
pp. 24-30 ◽  
Author(s):  
Miguel A. De la Rosa ◽  
Antonio J. Márquez ◽  
José M. Vega
Keyword(s):  
Nitrate Reductase ◽  
Reductase Activity ◽  
Prosthetic Group ◽  
Original Activity ◽  
Enzyme Preparations ◽  
Fluorescence Studies ◽  
Transport Chain ◽  
Sulphydryl Groups ◽  
Nadh Cytochrome

Ankistrodesmus braunii NAD(P)H-nitrate reductase is a complex hemoflavomolybdoprotein composed by eight similar subunits. The flavin prosthetic group, identified as FAD, is essential for the NAD(P)H-dependent activities of the complex, and is located before the heme chromo- phore in the enzyme electron transport chain from reduced pyridine nucleotides to nitrate. Fluorescence studies indicate that nitrate reductase can dissociate about 80% of its FAD by incubation at room temperature, the flavin dissociation being followed by a parallel decrease of NADH-nitrate reductase activity. Dissociation of FAD from the protein is easily increased by dilution or prolonged dialysis of the enzyme preparations. However, exogenous FAD specifically prevents the dissociation of enzyme-bound flavin, and protects the NAD(P)H-dependent activities. The Km for FAD, as a protector of NADH-cytochrome c reductase activity, is 4 nᴍ. In addition, dithioerythritol also prevents the flavin dissociation, and therefore the presence of free sulphydryl groups in the FAD-domain is suggested. FAD-depleted nitrate reductase, obtained by several methods, is unable to recover its original activity when incubated in the presence of FAD alone or with thiols.

scholarly journals Ouabain binding to phospholipid-dependent adenosine triphosphatase

1978 ◽  
Vol 169 (2) ◽  
pp. 313-320 ◽  
Author(s):  
S L Goodman ◽  
K P Wheeler
Keyword(s):  
Atpase Activity ◽  
Protein Complex ◽  
Adenosine Triphosphatase ◽  
Rabbit Kidney ◽  
Ouabain Binding ◽  
Equilibrium Conditions ◽  
Enzyme Preparations

The role of phospholipid in the binding of ouabain to the (Na+ + K+)-dependent adenosine triphosphatase was studied. Enzyme preparations obtained from rabbit kidney were treated with Lubrol WX to remove the phospholipid component essential for ATPase activity. Reconstituted enzyme samples were prepared by the addition of phosphatidylserine and sedimentation of an enzymically active lipid-protein complex. The binding of ouabain to both kinds of preparations was measured under equilibrium conditions with the use of 3H-labelled ouabain and initial ouabain concentrations in the range 0.01-1 micrometer. The main findings were: (i) (Mg2+ + Pi) promoted binding of significant quantities of ouabain only to the reconstituted enzyme; (ii) the absence of added Na+, (Mg2+ + ATP) similarly promoted binding only to the reconstituted samples; (iii) the addition of Na+ in the presence of (Mg2+ + ATP) increased the amount of ouabain bound to the reconstituted enzyme when the ouabain concentration was below about 0.1 micrometer, but it had no effect when the ouabain concentration was about 1 micrometer; (iv) (Mg2+ + ATP) induced ouabain binding to the depleted enzyme only when Na+ was also added; (v) the amount of ouabain bound to both depleted and reconstituted enzymes was the same in the presence of (Mg2+ + ATP + Na+); (vi) the reconstituted enzyme appeared to have a greater affinity for Na+ than did the depleted enzyme.

scholarly journals The characterization of two reduced nicotinamide–adenine dinucleotide phosphate-linked aldehyde reductases from pig brain

1972 ◽  
Vol 130 (3) ◽  
pp. 765-772 ◽  
Author(s):  
A. J. Turner ◽  
K. F. Tipton
Keyword(s):  
Deae Cellulose ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Aldehyde Reductase ◽  
Enzyme Preparations ◽  
Pig Brain ◽  
Michaelis Constants ◽  
Probable Role ◽  
Reduced Nicotinamide Adenine Dinucleotide

1. NADPH-linked aldehyde reductase from pig, ox and rat brain exhibits non-linear reciprocal plots when partially purified enzyme preparations are studied. 2. In pig brain this non-linearity is due to the presence of two distinct aldehyde reductases, which can be separated by DEAE-cellulose chromatography. 3. These two enzymes can be distinguished by several criteria, including pH optima, Michaelis constants for substrates and their inhibitor sensitivity. 4. The probable role of these enzymes in the metabolism of the aldehydes derived from the biogenic amines is discussed.

scholarly journals The Antiviral and Cancer Genomic DNA Deaminase APOBEC3H Is Regulated by a RNA-Mediated Dimerization Mechanism

2017 ◽  
Author(s):  
Nadine M. Shaban ◽  
Ke Shi ◽  
Kate V. Lauer ◽  
Michael A. Carpenter ◽  
Christopher M. Richards ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Rna Binding ◽  
Cytosine Deaminase ◽  
Rnase A ◽  
Binding Motif ◽  
Innate And Adaptive Immunity ◽  
Enzyme Preparations ◽  
Gene Diversification ◽  
Hiv 1

SUMMARYHuman APOBEC3H and homologous single-stranded DNA cytosine deaminases are unique to mammals. These DNA editing enzymes function in innate immunity by restricting the replication of viruses and transposons. Misregulated APOBEC3H also contributes to cancer mutagenesis. Here we address the role of RNA in APOBEC3H regulation. APOBEC3H co-purifies with RNA as an inactive protein, and RNase A treatment yields enzyme preparations with stronger DNA deaminase activity. RNA binding-defective mutants are DNA hypermutators. Chromatography profiles and crystallographic data demonstrate a mechanism in which double-stranded RNA mediates enzyme dimerization. RNA binding is required for APOBEC3H cytoplasmic localization and for packaging into HIV-1 particles and antiviral activity. Related DNA deaminases including other APOBEC3 family members and the antibody gene diversification enzyme AID also bind RNA and are predicted to have a similar RNA binding motif suggesting mechanistic conservation and relevance to innate and adaptive immunity and to multiple diseases.HIGHLIGHTSRNA inhibits human APOBEC3H DNA cytosine deaminase activityRNA binding mutants are DNA hypermutatorsX-ray structure demonstrates an RNA duplex-mediated APOBEC3H dimerization mechanismRNA binding is required for packaging into HIV-1 particles and antiviral activity

Poultry farming: current questions and answers

2020 ◽  
Author(s):  
Tamara Okolelova ◽  
Syergyey YEngashyev ◽  
Ivan Yegorov
Keyword(s):  
Biologically Active Substances ◽  
Biologically Active ◽  
Mixed Feed ◽  
Nutritional Factors ◽  
Enzyme Preparations ◽  
Questions And Answers ◽  
Active Substances ◽  
Poultry Farming

In the book in the form of questions and answers considerable attention is paid to data on the needs of all types of poultry in nutritional, mineral and biologically active substances, taking into account age of poultry. The characteristic of the main feed products is given, and the rational norms for including them in mixed feed for poultry are indicated. The role of vitamins, macro- and microelements, enzyme preparations, probiotics, prebiotics, antibiotics, organic acids, antioxidants, emulsifiers and other sources of biologically active substances in poultry nutrition is shown. Both nutritional factors that reduce the immune system and the causes of major feed diseases, which are related to the quality of feed, with violations in the rationing of nutrients and minerals, are indicated, and also biologically active substances, technologies for feeding and keeping poultry, methods of their prevention are given. It is addressed to specialists and managers of poultry farms, feed industry enterprises, researchers, postgraduates and students.

scholarly journals THE EMERGING ROLE OF SERRATIOPEPTIDASE IN ORAL SURGERY: LITERATURE UPDATE

2018 ◽  
Vol 11 (3) ◽  
pp. 19 ◽  
Author(s):  
Santhosh Kumar Mp
Keyword(s):  
Proteolytic Enzyme ◽  
Therapeutic Agent ◽  
Oral Surgery ◽  
Maxillofacial Surgery ◽  
Oral And Maxillofacial Surgery ◽  
Medical Field ◽  
Enzyme Preparations ◽  
Inflammatory Agent ◽  
Anti Inflammatory

 Serratiopeptidase, a proteolytic enzyme derived from Serratia E-15 species enterobacteria, is widely used in medical field for its anti-inflammatory, anti-edemic properties, and analgesic properties. It is being used commonly in various specialties such as orthopedics, otolaryngology, gynecology, surgery, pulmonology, ophthalmology, and dentistry. Research has shown that serratiopeptidase is the most effective anti-inflammatory agent compared to other enzyme preparations. This article reviews the efficacy, safety, and applications of serratiopeptidase in oral surgery. This article also discusses the mechanism of action of serratiopeptidase, its contraindications and complications. From the recently published literature, it is clear that the role of serratiopeptidase as a therapeutic agent in oral and maxillofacial surgery is expanding and they hold a promising future as a broad-spectrum anti-inflammatory drug with minimal side effects and complications. Further, research will broaden their applications in the field of medicine and dentistry.

scholarly journals Isolation and properties of a ‘malic’ enzyme from cauliflower bud mitochondria

1971 ◽  
Vol 122 (4) ◽  
pp. 495-501 ◽  
Author(s):  
A. R. Macrae
Keyword(s):  
Malic Enzyme ◽  
Tricarboxylic Acid Cycle ◽  
Decarboxylase Activity ◽  
Enzyme Preparations ◽  
Ph Values ◽  
Low Concentrations ◽  
Absolute Requirement ◽  
Nad Oxidoreductase ◽  
Regulatory Properties

1. A ‘malic’ enzyme [l-malate–NAD oxidoreductase (decarboxylating), EC 1.1.1.39] has been isolated from cauliflower bud mitochondria and partially purified. 2. The enzyme is specific for l-malate and has an absolute requirement for either Mn2+, Co2+ or Mg2+. 3. The enzyme shows activity with both NAD+ and NADP+, but NAD+ is the preferred cofactor. 4. No appreciable oxaloacetate decarboxylase activity is present in the enzyme preparations even at low pH values. 5. The enzyme is inhibited by NADH and by oxaloacetate and stimulated by SO42− and by low concentrations of CoA. 6. The regulatory properties of the enzyme support the proposed role of the enzyme in the utilization of tricarboxylic acid-cycle acids for energy production when glycolysis is suppressed.

Role of peroxidase and esterase activities during cotton fiber development

1986 ◽  
Vol 5 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Vrinda S. Thaker ◽  
Sant Saroop ◽  
Pankaj P. Vaishnav ◽  
Yash Dev Singh
Keyword(s):  
Cotton Fiber ◽  
Fiber Development ◽  
Cotton Fiber Development ◽  
Esterase Activities
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