CHARACTERIZATION OF HUMAN OVARIAN OESTRADIOL-17β OXIDOREDUCTASE ACTIVITY

1977 ◽  
Vol 85 (3) ◽  
pp. 624-635 ◽  
Author(s):  
Donald E. Pittaway ◽  
Richard N. Andersen ◽  
James R. Givens
Keyword(s):  
Enzyme Activity ◽  
Enzyme Activities ◽  
Enzyme Preparation ◽  
Phenolic Hydroxyl ◽  
Supernatant Fraction ◽  
Oxidoreductase Activity ◽  
Sulfhydryl Reagent ◽  
Michaelis Constants ◽  
Human Ovaries

ABSTRACT Oestradiol-17β oxidoreductase activity, which catalyzes the interconversion of oestrone and oestradiol, was investigated in preparations of human ovaries. The enzyme activities were localized primarily in the 105 000 × g supernatant fraction; dialyzed supernatant preparations were used in subsequent studies. The pH optima were 6.9 for reduction and 8.1 for 17β-dehydrogenation. The apparent Michaelis constants for oestrone and oestradiol were 1 × 10-7 m and 5 × 10-7 m, respectively. The enzyme activity was present with either NADP(H) or NAD(H), though NADP(H) were the preferred cofactors. Non-aromatic steroids androstenedione, dehydroepiandrosterone, testosterone and 5-androstene-3β,17β-diol were poor substrates for the enzyme preparation. Methylation of the phenolic hydroxyl of oestrone and oestradiol resulted in slightly enhanced activities. The sulfhydryl reagent, N-ethylmaleimide, inhibited the reduction of oestrone. A dialyzed supernatant preparation retained approximately 79 % of the original enzyme activity when stored at −20°C for 6 weeks.

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.

IMMOBILIZATION OF AMYLASE PRODUCING BACTERIA (BACILLUS SUBTILIS) FROM SOIL OF WESTERN HIMALAYAN REGION SOLAN, HIMACHAL PRADESH, INDIA

2021 ◽  
pp. 109-115
Author(s):  
ARUN KUMAR ◽  
POONAM KUMARI ◽  
KASAHUN GUDETA ◽  
JM JULKA
Keyword(s):  
Enzyme Activity ◽  
Bacillus Subtilis ◽  
Physicochemical Properties ◽  
Bacterial Strain ◽  
Enzyme Activities ◽  
Enzyme Assay ◽  
Himachal Pradesh ◽  
Genus Bacillus ◽  
Western Himalayan Region

Objective: The paper aimed to immobilize amylase producing bacterial strain on a suitable matrix and characterization of its physicochemical properties so that much amount of amylase could be produced to be applied in different industries. Methods: Bacterial colonies were sub-cultured from samples collected from soil in freshly prepared dishes containing starch agar by dot method using sterile inoculating needles from which five different bacteria belonged to genus Bacillus were isolated and assigned as A1, A2, A3, A4, and A5. Results: It was found that A1 displayed the highest enzyme activity of 17.89 IU/ml with enzyme assay of 0.83 mg/ml and the bacterium was identified to be Bacillus subtilis. A5 displayed 10.13 IU/ml with protein contents of 0.11 mg/ml indicated that A1 possess the highest enzyme activities which were categorized under Bacillus and protein contents and A5 showed less amount of enzyme activities and protein contents as compared to other. Conclusion: The bacteria which were produced much amount of enzyme activities identified as Bacillus subtilis and recommended and have been recommended to be cultured for the production of amylase enzyme.

scholarly journals Purification and immunochemical characterization of monoamine oxidase from rat and human liver

1977 ◽  
Vol 161 (1) ◽  
pp. 167-174 ◽  
Author(s):  
R G Dennick ◽  
R J Mayer
Keyword(s):  
Enzyme Activity ◽  
Monoamine Oxidase ◽  
Enzyme Activities ◽  
Gel Electrophoresis ◽  
Human Liver ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Triton X

1. Monoamine oxidase from rat and human liver was purified to homogeneity by the criterion of polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. 2. The enzyme activity was extracted from mitochondrial preparations by Triton X-100. The enzyme was purified by (NH4)2SO4 fractionation followed by chromatography on DEAE-cellulose, Sepharose 6B, spheroidal hydroxyapatite, and finally chromatography on diazo-coupled tyramine-Sepharose. 3. Distinct differences occur in the chromatographic behaviour of the two enzymes on both DEAE-cellulose and spheroidal hydroxyapatite. 4. It is unlikely that the purification of the enzymes on tyramine-Sepharose is due to affinity chromatography and reasons for this are discussed. 5. The purified enzymes did not oxidize-5-hydroxytryptamine and the relative activities of the enzymes with benzylamine were increased approx. 1.25-fold compared with the enzyme activities of mitochondrial preparations. 6. Immunotitration of enzyme activity in extracts of mitochondrial preparations from rat liver was carried out with 5-hydroxytryptamine, tyramine and benzylamine. The enzyme activities were completely immunoprecipitated by the same volume of antiserum. Similar results were obtained with the antiserum to the enzyme from human liver.

scholarly journals PHYSIOLOGICAL CHARACTERIZATION OF POLAR Tn5-INDUCED ISOLEUCINE-VALINE AUXOTROPHS IN ESCHERICHIA COLI K-12: EVIDENCE FOR AN INTERNAL PROMOTER IN THE ilvOGEDA OPERON

Genetics ◽  
1979 ◽  
Vol 93 (2) ◽  
pp. 309-319
Author(s):  
Claire M Berg ◽  
Karen J Shaw ◽  
Joyce Vender ◽  
Maryla Borucka-Mankiewicz
Keyword(s):  
Escherichia Coli ◽  
Enzyme Activity ◽  
Transposable Element ◽  
Feeding Behavior ◽  
Enzyme Activities ◽  
Internal Promoter ◽  
Physiological Characterization ◽  
Growth Requirements ◽  
K 12

ABSTRACT The properties of 22 isoleucine-valine auxotrophs induced in Escherichia coli K-12 by the transposable element, Tn5, were characterized on the basis of growth requirements, cross-feeding behavior, and enzyme activity. Mutants defective in ilvA, ilvC, ilvD and ilvE were found. Mutations in ilvE were not completely polar on ilvD and ilvA enzyme activities (that is, ilvE mutants possessed a low constitutive level of expression of the enzymes coded by ilvD and ilvA), while mutations in ilvD were completely polar on ilvA enzyme activity. The data suggest that there is an internal promoter between the sites of Tn5 insertion in ilvE and ilvD.

scholarly journals Immunochemical characterization of phosphatidylinositol 4-phosphate kinase from rat brain

1986 ◽  
Vol 233 (3) ◽  
pp. 859-864 ◽  
Author(s):  
C J van Dongen ◽  
J W Kok ◽  
L H Schrama ◽  
A B Oestreicher ◽  
W H Gispen
Keyword(s):  
Enzyme Activity ◽  
Catalytic Activity ◽  
Rat Brain ◽  
Enzyme Preparation ◽  
Kinase Activity ◽  
Deae Cellulose ◽  
Phosphatidylinositol 4 ◽  
Sepharose 4B ◽  
Brain Cytosol

Affinity-purified antibodies were used to identify a protein of molecular mass 45 kDa (45 kDa protein) in rat brain cytosol as phosphatidylinositol 4-phosphate (PtdIns4P) kinase. Antibodies were raised in rabbits by immunization with the purified 45 kDa protein. Anti-(45 kDa protein) immunoglobulins were isolated by affinity chromatography of the antiserum on a solid immunosorbent, which was prepared by coupling a soluble rat brain fraction, the DEAE-cellulose pool containing 10-15% 45 kDa protein, to CNBr-activated Sepharose 4B. The purified IgGs were specific for the 45 kDa protein as judged by immunoblot and by immunoprecipitation. The purified anti-(45 kDa protein) IgGs inhibited the enzyme activity of partially purified PtdIns4P kinase, whereas preimmune IgGs were ineffective. Immunoprecipitation of the 45 kDa protein from the partially purified enzyme preparation with the purified IgGs resulted in a concomitant decrease in the amount of 45 kDa protein and in PtdIns4P kinase activity. The amount of 45 kDa protein remaining in the supernatant and the activity of PtdIns4P kinase correlated with a coefficient of r = 0.87. The evidence presented lends further support for the notion that the catalytic activity of PtdIns4P kinase in rat brain cytosol resides in a 45 kDa protein.

scholarly journals In vitro conversion of proapoprotein A-I to apoprotein A-I. Partial characterization of an extracellular enzyme activity.

1983 ◽  
Vol 258 (19) ◽  
pp. 11430-11433 ◽  
Author(s):  
C Edelstein ◽  
J I Gordon ◽  
K Toscas ◽  
H F Sims ◽  
A W Strauss ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Extracellular Enzyme ◽  
Extracellular Enzyme Activity ◽  
Partial Characterization

scholarly journals Partial purification and biochemical characterization of a new highly acidic NYSO laccase from Alcaligenes faecalis

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Soad A. Abdelgalil ◽  
Ahmad R. Attia ◽  
Reyed M. Reyed ◽  
Nadia A. Soliman
Keyword(s):  
Enzyme Activity ◽  
Sodium Dodecyl ◽  
Alcaligenes Faecalis ◽  
Maximum Activity ◽  
Sodium Oxalate ◽  
Partial Purification ◽  
Bromophenol Blue ◽  
Bromocresol Purple ◽  
Laccase Enzyme

Abstract Background Due to the multitude industrial applications of ligninolytic enzymes, their demands are increasing. Partial purification and intensive characterization of contemporary highly acidic laccase enzyme produced by an Egyptian local isolate designated Alcaligenes faecalis NYSO were studied in the present investigation. Results Alcaligenes faecalis NYSO laccase has been partially purified and intensively biochemically characterized. It was noticed that 40–60% ammonium sulfate saturation showed maximum activity. A protein band with an apparent molecular mass of ~ 50 kDa related to NYSO laccase was identified through SDS-PAGE and zymography. The partially purified enzyme exhibited maximum activity at 55 °C and pH suboptimal (2.5–5.0). Remarkable activation for enzyme activity was recognized after 10-min exposure to temperatures (T) 50, 60, and 70 °C; time elongation caused inactivation, where ~ 50% of activity was lost after a 7-h exposure to 60 °C. Some metal ions Cu2+, Zn2+, Co2+, Ni2+, Mn2+, Cd2+, Cr2+, and Mg2+ caused strong stimulation for enzyme activity, but Fe2+ and Hg2+ reduced the activity. One millimolar of chelating agents [ethylenediamine tetraacetic acid (EDTA), sodium citrate, and sodium oxalate] caused strong activation for enzyme activity. Sodium dodecyl sulfate (SDS), cysteine-HCl, dithiothreitol (DTT), β-mercaptoethanol, thioglycolic acid, and sodium azide caused strong inhibition for NYSO laccase activity even at low concentration. One millimolar of urea, imidazole, kojic acid, phenylmethylsulfonyl fluoride (PMSF), H2O2, and Triton X-100 caused activation. The partially purified NYSO laccase had decolorization activity towards different dyes such as congo red, crystal violet, methylene blue, fast green, basic fuchsin, bromophenol blue, malachite green, bromocresol purple eriochrome black T, and Coomassie Brilliant Blue R-250 with various degree of degradation. Also, it had a vast range of substrate specificity including lignin, but with high affinity towards p-anisidine. Conclusion The promising properties of the newly studied laccase enzyme from Alcaligenes faecalis NYSO strain would support several industries such as textile, food, and paper and open the possibility for commercial use in water treatment. It will also open the door to new applications due to its ligninolytic properties in the near future.

Sign in / Sign up

Export Citation Format

Share Document