ÜBER DEN ENZYMATISCHEN ABBAU VON D,L-3-METHOXY-4-HYDROXY-MANDELSÄURE ZU VANILLINSÄURE

1969 ◽  
Vol 61 (1) ◽  
pp. 104-110 ◽  
Author(s):  
Wilhelm Dirscherl ◽  
Betty Brisse
Keyword(s):  
Enzymatic Activity ◽  
Pseudomonas Fluorescens ◽  
Rat Liver ◽  
Mandelic Acid ◽  
Glyoxylic Acid ◽  
Type Iv ◽  
Quantitative Measurements ◽  
Nad Oxidoreductase ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

ABSTRACT The dehydrogenation of DL-3-methoxy-4-hydroxy-mandelic acid to 3-methoxy-4-hydroxyphenyl-glyoxylic acid by fractions of the rat liver, 20β-hydroxy-steroid-dehydrogenase (1. 1. 1.53, C = 20-dihydrocortisone: NAD oxidoreductase) and cells of pseudomonas fluorescens Type IV, as well as fractions obtained of this strain, was proved by paper chromatography of the incubation extracts. Quantitative measurements and kinetic research was only possible with cells of pseudomonas fluorescens and fractions obtained of them. The enzymatic activity is bound to the particles of the pseudomonas cells and the microsomes of the rat liver. Until now it was only possible to get just a small amount into solution.

scholarly journals The comparative specificity of three oestradiol-binding proteins. Rat α-foetoprotein, rat liver 17β-hydroxy steroid dehydrogenase and anti-(oestradiol-6-carboxymethyloxime-bovine serum albumin) antiserum

1975 ◽  
Vol 151 (3) ◽  
pp. 513-518 ◽  
Author(s):  
C Laurant ◽  
S D de Lauzon ◽  
N Cittanova ◽  
E Nunez ◽  
M F Jayle
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Rat Liver ◽  
Bovine Serum ◽  
Binding Proteins ◽  
Specific Binding ◽  
Naturally Occurring ◽  
Γ Globulins ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

1. The specificity of 3 oestradiol-binding proteins was studied. Two of these proteins are naturally occurring (rat α-foetoprotein and rat liver microsomal 17β-hydroxy steroid dehydrogenase) and the third is an artificially induced model, anti-(oestradiol-6-carboxymethyloxime-bovine serum albumin) γ-globulins. 2. A specific binding procedure for each protein model permitted a determination of its affinity for oestradiol and for 30 other steroids. 3. The results obtained have brought to light the different areas of the steroid molecule that are important for its recognition by each of the three proteins. The two naturally occurring proteins (α-foetoprotein and 17β-hydroxy steroid dehydrogenase) recognize the edge of the steroid defined by C-4, C-6, C-8 and C-15. On the other hand, the γ-globulins recognize the opposite edge, i.e. that defined by C-2, C-10, C-11 and C-17. 4. Diethylstilboestrol, whose structure is analogous to that of a steroid, is only recognized by the two naturally occurring proteins.

scholarly journals Competition of two substrates for a single enzyme. A simple kinetic theorem exemplified by a hydroxy steroid dehydrogenase reaction

1969 ◽  
Vol 112 (3) ◽  
pp. 331-334 ◽  
Author(s):  
T. Pocklington ◽  
J. Jeffery
Keyword(s):  
Initial Rate ◽  
Maximum Velocity ◽  
Total Rate ◽  
Dehydrogenase Reaction ◽  
Rate Of Reaction ◽  
Nad Oxidoreductase ◽  
Lower Maximum ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase ◽  
Single Enzyme

1. If two compounds are substrates for a single enzyme, and do not form any ternary complex with the enzyme or combine directly with each other, then the total initial rate of reaction for a mixture of the two compounds may be greater than the rate for either compound alone, or may lie between the rates for the compounds alone. It is the concentration of the compound with the higher maximum velocity that determines which applies, and there is one concentration of the compound of higher maximum velocity at which the total rate of reaction is independent of the presence or absence of the substrate of lower maximum velocity. The values concerned are derived. 2. An example is given of 5α-androstan-3-one and 5α-androstane-3,16-dione as substrates competing for a hydroxy steroid–NAD oxidoreductase (EC 1.1.1.53).

scholarly journals 3-Hydroxy steroid dehydrogenase activities of cortisone reductase

1973 ◽  
Vol 135 (4) ◽  
pp. 881-888 ◽  
Author(s):  
William Gibb ◽  
Jonathan Jeffery
Keyword(s):  
Binding Site ◽  
Substrate Molecule ◽  
Ring Junction ◽  
Nad Oxidoreductase ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

The behaviour of various C19 and C18 steroids as substrates for crystalline preparations of cortisone reductase (EC 1.1.1.53) is described. 3α(Axial,3R)-, 3α(equatorial,3R)- and 3β(axial,3S)-hydroxy steroid–NAD oxidoreductase activities are demonstrated. Four pairs of the substrates differed only in the shape of the a/b ring junction, three pairs differed only in substitution at C-10, and four pairs differed only in substitution in ring d. The shape of the substrate molecule and certain substituents (e.g. 10β-methyl, 17β-hydroxy, 16-oxo or 17-oxo) altered substrate behaviour, but steroids differing considerably in shape nevertheless acted as substrates, suggesting the possibility of a large or flexible binding site. Km values varied about 10-fold, many being approx. 140μm. Vmax. values covered a greater range (about 200-fold) and the good substrates had high Vmax. values rather than low Km values.

A metabolic stability determination of Tetrahydrothiazolopyridine derivative a selective 11β-hydroxy steroid dehydrogenase type 1 (11β-hsd1) inhibitor

2017 ◽  
Vol 8 (3) ◽  
Author(s):  
MURUGESH KANDASAMY ◽  
MUHAMMED SALIHIN ◽  
MALLIKARJUNA RAO PICHIKA ◽  
SLAVKO KOMARNYTSKY ◽  
THIRUMURUGAN RATHINASABAPATHY
Keyword(s):  
Metabolic Stability ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

DIFFICULTIES IN THE DIAGNOSIS OF THE ADRENOGENITAL SYNDROME IN INFANCY

PEDIATRICS ◽  
1972 ◽  
Vol 49 (2) ◽  
pp. 198-205
Author(s):  
C. H. Shackleton ◽  
F. L. Mitchell ◽  
J. W. Farquhar
Keyword(s):  
Hydroxylase Deficiency ◽  
Adrenogenital Syndrome ◽  
Steroid Excretion ◽  
21 Hydroxylase Deficiency ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

Pregnanetriol was not excreted by an infant (7 days old) who was later shown to have a defect in steroid 21-hydroxylase. However, the excretion of this compound increased during the following days (1.2 mg on the thirteenth day of life). A high excretion of 3β-hydroxy-Δ steroids was the most noticeable abnormality in steroid excretion noted on the seventh day of life (e.g., 3β, 16α-dihydroxy-5-pregnen-20-one, 15 mg; 3β, 21-dihydroxy-5-pregnen-20-one, 1.4 mg and 3β, 16α-dihydroxy-5-androsten-17-one, 7.4 mg). This high 3β-hydroxy-Δ steroid excretion results in difficulties in distinguishing a defect in 3β-hydroxy steroid dehydrogenase from a 21-hydroxylase deficiency. At the age of 14 months the principal steroids excreted were those predominant in other cases of 21-hydroxylase deficiency, viz. pregnanetriol and 5β-pregnane-3α, 17α, 20α-triol-11-one (11-oxo-pregnanetriol).

METHYLATION OF THE 3-OH POSITION OF CATECHOL ACIDS BY RAT LIVER AND KIDNEY PREPARATIONS

1958 ◽  
Vol 36 (5) ◽  
pp. 491-497 ◽  
Author(s):  
J. Pellerin ◽  
A. D'Iorio
Keyword(s):  
Enzymatic Activity ◽  
Rat Liver ◽  
Paper Chromatography ◽  
Reduced Glutathione ◽  
Liver Homogenate ◽  
Supernatant Fraction ◽  
Hydroxybenzoic Acid ◽  
Dihydroxybenzoic Acid ◽  
Kidney Homogenate ◽  
Liver And Kidney

3,4-Dihydroxybenzoic acid, 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxymandelic acid, and 3,4-dihydroxycinnamic acid were separately incubated with L-methionine-methyl-C14 in the presence of rat liver or kidney homogenate. In each case, the radioactive metabolite separated by paper chromatography was found to have migrating properties similar to those of the 3-methoxy-4-hydroxyphenolic acid. This reaction was enhanced by the addition of ATP, Mg++, and reduced glutathione. When 3-hydroxybenzoic acid was incubated in this medium no methylated derivative was obtained. Preliminary experiments indicated that the enzymatic activity was contained mostly in the supernatant fraction. It was also noted that liver homogenate was much more active than kidney homogenate in methylating catechol acids.

Bestimmung des Molekulargewichtes der 20-β-Hydroxy-steroid-dehydrogenase

1962 ◽  
Vol 17 (7) ◽  
pp. 432-436 ◽  
Author(s):  
Matatiahu Gehatia
Keyword(s):  
Molecular Weight ◽  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Specific Volume ◽  
Sedimentation Coefficient ◽  
Partial Specific Volume ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

The enzyme 20-β-Hydroxy-steroid-dehydrogenase obtained from the culture of Streptomyces hydrogenans and dissolved in 0.05 M Tris puffer, pH 7.3, has been investigated by means of a ultracentrifuge at 20 °C. The sedimentation- as well as the diffusion-coefficients obtained from various solutions at different concentrations were extrapolated to the concentration c = 0. The resulting zero-value for the sedimentation coefficient is s0 = 6.64 s and for the diffusion coefficient is D0 = 5.51 × 10-7 cm2/sec. Supposing the partial specific volume of the enzyme under consideration analogously to other similar proteins is V+=0.749 ml/g, the molecular weight has been estimated as M = 118 400.

scholarly journals Comparative Analysis of the Conversion of Mandelonitrile and 2-Phenylpropionitrile by a Large Set of Variants Generated from a Nitrilase Originating from Pseudomonas fluorescens EBC191

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4232 ◽  
Author(s):  
Stolz ◽  
Eppinger ◽  
Sosedov ◽  
Kiziak
Keyword(s):  
Pseudomonas Fluorescens ◽  
Mandelic Acid ◽  
Single Point ◽  
Enantiomeric Excess ◽  
Point Mutations ◽  
General Information ◽  
Large Set ◽  
Single Point Mutations ◽  
Aliphatic Nitriles ◽  
Relationship Of

The arylacetonitrilase from the bacterium Pseudomonas fluorescens EBC191 has been intensively studied as a model to understand the molecular basis for the substrate-, reaction-, and enantioselectivity of nitrilases. The nitrilase converts various aromatic and aliphatic nitriles to the corresponding acids and varying amounts of the corresponding amides. The enzyme has been analysed by site-specific mutagenesis and more than 50 different variants have been generated and analysed for the conversion of (R,S)-mandelonitrile and (R,S)-2-phenylpropionitrile. These comparative analyses demonstrated that single point mutations are sufficient to generate enzyme variants which hydrolyse (R,S)-mandelonitrile to (R)-mandelic acid with an enantiomeric excess (ee) of 91% or to (S)-mandelic acid with an ee-value of 47%. The conversion of (R,S)-2-phenylpropionitrile by different nitrilase variants resulted in the formation of either (S)- or (R)-2-phenylpropionic acid with ee-values up to about 80%. Furthermore, the amounts of amides that are produced from (R,S)-mandelonitrile and (R,S)-2-phenylpropionitrile could be changed by single point mutations between 2%–94% and <0.2%–73%, respectively. The present study attempted to collect and compare the results obtained during our previous work, and to obtain additional general information about the relationship of the amide forming capacity of nitrilases and the enantiomeric composition of the products.

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