INHIBITORY EFFECTS OF 3,5-DIIODO-4-HYDROXYBENZOIC ACID ON THE CATECHOL-O-METHYLTRANSFERASE ACTIVITY IN A CRUDE ENZYME PREPARATION

1962 ◽  
Vol 40 (10) ◽  
pp. 1454-1456 ◽  
Author(s):  
A. D'Iorio ◽  
C. Mavrides
Keyword(s):  
Enzyme Preparation ◽  
Crude Enzyme ◽  
Hydroxybenzoic Acid ◽  
Inhibitory Effects ◽  
Methyltransferase Activity ◽  
Crude Enzyme Preparation

IN VITRO EFFECTS OF SUBSTITUTED IODOPHENOLS ON CATECHOL-O-METHYLTRANSFERASE

1963 ◽  
Vol 41 (8) ◽  
pp. 1779-1784 ◽  
Author(s):  
A. D'Iorio ◽  
C. Mavrides
Keyword(s):  
Kinetic Study ◽  
Enzyme Preparation ◽  
Crude Enzyme ◽  
Present Series ◽  
Hydroxybenzoic Acid ◽  
Reversible Inhibition ◽  
Crude Enzyme Preparation ◽  
Series Of Experiments ◽  
In Vitro Effects

The kinetic study of a new inhibitor of catechol-O-methyltransferase, 3,5-diiodo-4-hydroxybenzoic acid (DIHBA), previously reported by the authors (1), shows it to act in a competitive fashion. Instead of the crude enzyme preparation of the early experiments, a partially purified enzyme has been used throughout the present series of experiments and new substances have been tested with respect to their inhibiting effects. Thus, O-methyl-DIHBA is found to be inactive, while 3,5-diiodosalicylic acid (DISA) inhibits competitively and 3,5-diiodo-4-hydroxypyridine (DIHP) noncompetitively as indicated by the Lineweaver and Burk plots.3,5-Diiodo-4-hydroxyphenylpyruvic acid (DIHPA) produces a progressive and partly reversible inhibition, while 3,5-diiodotyrosine (DIT) has no effect on the activity of the enzyme. m-Fluorotyrosine, o-fluorophenol, and o-iodophenol are similarly inactive.

IN VITRO EFFECTS OF SUBSTITUTED IODOPHENOLS ON CATECHOL-O-METHYLTRANSFERASE

1963 ◽  
Vol 41 (1) ◽  
pp. 1779-1784
Author(s):  
A. D'Iorio ◽  
C. Mavrides
Keyword(s):  
Kinetic Study ◽  
Enzyme Preparation ◽  
Crude Enzyme ◽  
Present Series ◽  
Hydroxybenzoic Acid ◽  
Reversible Inhibition ◽  
Crude Enzyme Preparation ◽  
Series Of Experiments ◽  
In Vitro Effects

The kinetic study of a new inhibitor of catechol-O-methyltransferase, 3,5-diiodo-4-hydroxybenzoic acid (DIHBA), previously reported by the authors (1), shows it to act in a competitive fashion. Instead of the crude enzyme preparation of the early experiments, a partially purified enzyme has been used throughout the present series of experiments and new substances have been tested with respect to their inhibiting effects. Thus, O-methyl-DIHBA is found to be inactive, while 3,5-diiodosalicylic acid (DISA) inhibits competitively and 3,5-diiodo-4-hydroxypyridine (DIHP) noncompetitively as indicated by the Lineweaver and Burk plots.3,5-Diiodo-4-hydroxyphenylpyruvic acid (DIHPA) produces a progressive and partly reversible inhibition, while 3,5-diiodotyrosine (DIT) has no effect on the activity of the enzyme. m-Fluorotyrosine, o-fluorophenol, and o-iodophenol are similarly inactive.

Production and Properties of a Bacterial Thermostable Exo-inulinase

2001 ◽  
Vol 56 (11-12) ◽  
pp. 1022-1028 ◽  
Author(s):  
Kristina Uzunova ◽  
Anna Vassileva ◽  
Margarita Kambourova ◽  
Viara Ivanova ◽  
Dimitrina Spasova ◽  
...  
Keyword(s):  
Enzyme Production ◽  
Enzyme Preparation ◽  
Batch Cultivation ◽  
Crude Enzyme ◽  
Growth Time ◽  
Bacillus Sp ◽  
High Thermostability ◽  
Crude Enzyme Preparation ◽  
Ph Range

Abstract Enzyme production of newly isolated thermophilic inulin-degrading Bacillus sp. 11 strain was studied by batch cultivation in a fermentor. The achieved inulinase and invertase activi­ ties after a short growth time (4.25 h) were similar or higher compared to those reported for other mesophilic aerobic or anaerobic thermophilic bacterial producers and yeasts. The investigated enzyme belonged to the exo-type inulinases and splitted-off inulin, sucrose and raffinose. It could be used at temperatures above 65 °C and pH range 5.5-7.5. The obtained crude enzyme preparation possessed high thermostability. The residual inulinase and inver­ tase activities were 92-98% after pretreatment at 65 °C for 60 min in the presence of substrate inulin.

scholarly journals Paenibacillus curdlanolyticus Strain B-6 Xylanolytic-Cellulolytic Enzyme System That Degrades Insoluble Polysaccharides

2006 ◽  
Vol 72 (4) ◽  
pp. 2483-2490 ◽  
Author(s):  
Patthra Pason ◽  
Khin Lay Kyu ◽  
Khanok Ratanakhanokchai
Keyword(s):  
Growth Phase ◽  
Enzyme Preparation ◽  
Enzyme System ◽  
Crude Enzyme ◽  
Cellulolytic Enzyme ◽  
Crude Enzyme Preparation ◽  
Multienzyme Complexes ◽  
Sds Page ◽  
Paenibacillus Curdlanolyticus ◽  
Cellulose Binding

ABSTRACT A facultatively anaerobic bacterium, Paenibacillus curdlanolyticus B-6, isolated from an anaerobic digester produces an extracellular xylanolytic-cellulolytic enzyme system containing xylanase, β-xylosidase, arabinofuranosidase, acetyl esterase, mannanase, carboxymethyl cellulase (CMCase), avicelase, cellobiohydrolase, β-glucosidase, amylase, and chitinase when grown on xylan under aerobic conditions. During growth on xylan, the bacterial cells were found to adhere to xylan from the early exponential growth phase to the late stationary growth phase. Scanning electron microscopic analysis revealed the adhesion of cells to xylan. The crude enzyme preparation was found to be capable of binding to insoluble xylan and Avicel. The xylanolytic-cellulolytic enzyme system efficiently hydrolyzed insoluble xylan, Avicel, and corn hulls to soluble sugars that were exclusively xylose and glucose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of a crude enzyme preparation exhibited at least 17 proteins, and zymograms revealed multiple xylanases and cellulases containing 12 xylanases and 9 CMCases. The cellulose-binding proteins, which are mainly in a multienzyme complex, were isolated from the crude enzyme preparation by affinity purification on cellulose. This showed nine proteins by SDS-PAGE and eight xylanases and six CMCases on zymograms. Sephacryl S-300 gel filtration showed that the cellulose-binding proteins consisted of two multienzyme complexes with molecular masses of 1,450 and 400 kDa. The results indicated that the xylanolytic-cellulolytic enzyme system of this bacterium exists as multienzyme complexes.

ENZYMIC DEGRADATION OF WHEAT BRAN TO IMPROVE ITS NUTRITIONAL VALUE FOR MONOGASTRICS

1969 ◽  
Vol 49 (2) ◽  
pp. 205-214 ◽  
Author(s):  
T. S. Neudoerffer ◽  
R. E. Smith
Keyword(s):  
Wheat Bran ◽  
Nutritional Value ◽  
Enzyme Preparation ◽  
Proteolytic Enzymes ◽  
Protein Digestibility ◽  
Reducing Sugar ◽  
Metabolizable Energy ◽  
Crude Enzyme ◽  
Sugar Accumulation ◽  
Crude Enzyme Preparation

The enzymic degradation of wheat bran using cellulolytic and proteolytic enzymes from a number of sources was investigated. Two enzyme combinations were found to be effective for the chemical alteration of wheat bran. Crude enzyme preparation from the fungus T. viride in combination with a commercial proteinase brought about a 32% reducing sugar accumulation, a 36% loss of holocellulose, a 40% loss of α-cellulose and a, 54% solubilization of protein. Crude enzyme preparation from the fungus M. verrucaria in combination with a commercial proteinase gave rise to a 27% reducing sugar accumulation, a 39% loss of holocellulose, a 22% loss of α-cellulose and 50% solubilization of protein. The nutritional value for the rat of wheat bran modified by either enzyme combination was significantly improved. Apparent protein digestibility was improved significantly. Preliminary experiments indicate that the modification of wheat bran increases the metabolizable energy.

Selective preparation of N-acetyl-D-glucosamine and N,N?-diacetylchitobiose from chitin using a crude enzyme preparation from Aeromonas sp.

2005 ◽  
Vol 27 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Ju Hee Kuk ◽  
Woo Jin Jung ◽  
Gyung Hyun Jo ◽  
Joon Seob Ahn ◽  
Kil Yong Kim ◽  
...  
Keyword(s):  
Enzyme Preparation ◽  
Crude Enzyme ◽  
Crude Enzyme Preparation

scholarly journals Ferrochelatase activity in the photosynthetic alga Cyanidium caldarium. Development of the enzyme during biosynthesis of photosynthetic pigments

1984 ◽  
Vol 220 (3) ◽  
pp. 861-863 ◽  
Author(s):  
S B Brown ◽  
J A Holroyd ◽  
D I Vernon ◽  
O T G Jones
Keyword(s):  
Photosynthetic Pigments ◽  
Enzyme Preparation ◽  
Crude Enzyme ◽  
Cyanidium Caldarium ◽  
Crude Enzyme Preparation

Dark-grown cells of the photosynthetic alga Cyanidium caldarium were shown to contain ferrochelatase activity, which increased markedly when the cells were induced to form pigments by exposure to light. Km values for the crude enzyme preparation were 14.8 microM and 6.5 microM for binding of Co2+ and deuteroporphyrin IX respectively.

Sign in / Sign up

Export Citation Format

Share Document