Aryl Acylamidase Research Articles

Rat brain aryl acylamidase: stereospecific inhibition by LSD and serotonin‐related compounds

Rat brain aryl acylamidase: stereospecific inhibition by LSD and serotonin‐related compounds

Rat brain de-acetylating activity: Stereospecific inhibition by LSD and serotonin-related compounds

A de-acetylase (aryl acylamidase, E.C.3.5.1.13) has been isolated and partially characterized from rat brain. Previous studies have shown that this enzymatic activity is inhibited by low concentrations of serotonin. This report examines the effects of closely related tryptamine derivatives and demonstrates that enzymatic activity is stereospecifically inhibited by LSD. Similar enzymatic activity from liver was found to be insensitive to any of the compounds tested. The significance of these findings with regard to well known serotonin-LSD interactions is discussed.

Aryl acylamidase activity in larvae of the webbing clothes moth, Tineola bisselliella

1. 1. Significant levels of aryl acylamidase (E.C. 3.5.1.13) activity have been found in extracts of larvae of the webbing clothes moth, Tineola bisselliella using acetyl p- nitroanilide as substrate. 2. 2. Gel electrophoresis suggests that the activity is due to more than one enzyme. Inhibitor studies show that these enzymes are probably of the “active serine” type but have a requirement for a free sulphydryl group. 3. 3. Partially purified enzyme will not catalyse the hydrolysis of N- acetyl groups from some simple α-N- acetyl or N- acetyl hexosamines.

An inducible amidase from pseudomonas striata

A mutant of Pseudomonas striata that grows in mineral medium with acetanilide as the sole carbon and nitrogen source for growth was isolated and a great amount of inducible enzyme was extracted from the cell. The crude enzyme extract was found to be very active toward the substrate acetanilide and the hydrolyzed products were identified as aniline and acetic acid. The enzyme was therefore characterized as an aryl acylamidase (EC 3.5.1.13). The growth and induction of the micro-organism as well as the extraction of the enzyme are described briefly in this paper.

Hydrolysis of 3′,4′-dichloropropionanilide by an aryl acylamidase from Taraxacum officinale

An aryl acylamidase (aryl-acylamine amidohydrolase, E.C. 3.5. 1.a) which hydrolyses the herbicide propanil (3′,4′-dichloropropionanilide), was isolated from dandelion roots and partially purified and characterized. Specificity tests on the enzyme revealed that it could hydrolyse various chlorine ring-substituted propionanilides and 3,4-dichloroanilide alkyl compounds. The partially purified enzyme was inhibited by several sulfhydryl reagents and metal ions. The pH optimum was broad, between 7·4 and 7·8. The apparent activation energy, determined from an Arrhenius plot, was 9·0 kcal/mol (37 700 J/mol) for the hydrolysis of 3′,4′-dichloropropionanilide. The apparent K m was 1·7 × 10 −4 M with propanil as substrate.

Inhibition of Phenylamide Hydrolysis by Bacillus sphaericus with Methylcarbamate and Organophosphorus Insecticides

The degradation of the phenylamide herbicides monolinuron, linuron, and solan by cultures of Bacillus sphaericus ATCC 12123 was inhibited by the methylcarbamate insecticides metmercapturon, aldicarb, propoxur, and carbaryl and by the organophosphorus insecticides fenthion and parathion. The extent of inhibition was largest with metmercapturon and smallest with parathion inhibition of hydrolysis of the two phenylurea herbicides was greater than of the acylanilide compound. Tests with crude enzyme preparations of aryl acylamidase derived from B. sphaericus showed that the inhibition of the hydrolysis of linuron with methylcarbamates is a competitive one. The insecticides tested did induce the enzyme, nor could they serve as its substrate.

Hydrolysis of 3′,4′‐dichloropropionanilide by plant aryl acylamidases

Summary: Résumé: ZusammenfassungThirty‐eight different agronomic and horticultural crop plants were tested for aryl acylamidase enzymes which could hydrolyse the amide bond of the herbicide, 3′,4′‐dichloropropion‐anilide (propanil). More than half of these plants, from ten different plant families, covering thirty genera, possessed enzymes capable of degrading propanil in this manner. Enzyme preparations from leaf lettuce (Lactuca sativa L.) appeared to be the richest source of aryl acylamidase activity. The total enzyme units present, as well as specific activities of enzymes from these plant tissue preparations, varied widely in the different plants.Hydrotyse du 3′,4′‐dichtoropropionanitide par des aryt acylamytases vegetates.Trente‐huit cultures différentes parmi lesquelles des plantes horticoles ont été essayées quant à la production d'aryl acylamylases, enzymes qui pourraient hydrolyser la liaison amidede l'herbicide 3′,4′‐dichloropropionanilide (propanil). Plus de la moitié de ces plantes appartenant 4 10 families différentes et représentant 30 genres possèdent des enzymes capables de dégrader le propanil de cette maniére. Des préparations enzymatiques effectuées à partir de la feuille de laitue (Lactuca sativa L.) se sont révélées être les sources les plus abondantes d'activité aryl acylamylase. Le total des unités enzymatiques présentes, aussi bien que les activités spécifiques des enzymes extraites de ces préparations de tissus végétaux ont varié de façon importante selon les especes vegétales.Hydrolyse von 3′,4′‐Dichlorpropionanilid durch pflanzliche ArytacytamidasenEs wurden 38 verschiedene landwirtschaftliche und gärtnerische Kulturpflanzen auf Arylacylamidase Enzyme untersucht, die die Amidbindung des Herbizids 3′,4′‐Dichlor‐propionanilid (Propanil) hydrolysieren konnten. Mehr als die Hälfte dieser Pflanzen, aus zehn verschiedenen Pflanzenfamilien, 30 Gattungen einschliessend, enthielten Enzyme, die Propanil auf diese Weise abzubauen vermochten. Enzymprapärationen von Kopfsalat (Lactuca sativa L.) schienen die ergiebigste Quelle für die Arylacylamidase‐Aktivität zu sein. Die insgesamt vorhandenen Enzymeinheiten, als auch die spezifischen Aktivitäten der Enzyme der Gewebepräparationen, schwankten bei den verschiedenen Pflanzen ziemlich stark.

Serotonin-sensitive aryl acylamidase in rat brain

Aryl acylamidase (E.C.3.5.1.13) was extracted from rat brain. The enzyme activity was inhibited by low concentrations of serotonin. The inhibition was non-competitive type and K i value was about 3 × 10 −5M. Tryptamine inhibited the enzyme to a lesser extent. Other amines such as noradrenaline, tyramine and histamine did not affect the enzyme reaction. In contrast, aryl acylamidase from rat liver was insensitive to serotonin.

Purification and properties of an aryl acylamidase of Bacillus sphaericus, catalyzing the hydrolysis of various phenylamide herbicides and fungicides.

From Bacillus sphaericus ATCC 12123 an aryl acylamidase (EC 3.5.1.13) was purified to homogeneity by ion exchange chromatography, gel filtration, and polyacrylamide gel electrophoresis. The enzyme is inducible by various phenylamides of the acylanilide, phenylcarbamate, and methoxysubstituted phenylurea type. It has a molecular weight of 75,000. Enzyme activity was inhibited by sulfhydryl reagents, several metal ions, and 3,4-dichloroaniline (a product of linuron degradation). A requirement for divalent metal ions in enzyme activity could not be demonstrated. In the presence of 6 M urea an irreversible inactivation of the enzyme occurred. The hydrolysis of L-alanine-4-nitroanilide was competitively inhibited by puromycin.

Purification and Properties of an Aryl Acylamidase of Bacillus sphaericus, Catalyzing the Hydrolysis of Various Phenylamide Herbicides and Fungicides

From Bacillus sphaericus ATCC 12123 an aryl acylamidase (EC 3.5.1.13) was purified to homogeneity by ion exchange chromatography, gel filtration, and polyacrylamide gel electrophoresis. The enzyme is inducible by various phenylamides of the acylanilide, phenylcarbamate, and methoxysubstituted phenylurea type. It has a molecular weight of 75,000. Enzyme activity was inhibited by sulfhydryl reagents, several metal ions, and 3,4-dichloroaniline (a product of linuron degradation). A requirement for divalent metal ions in enzyme activity could not be demonstrated. In the presence of 6 M urea an irreversible inactivation of the enzyme occurred. The hydrolysis of L-alanine-4-nitroanilide was competitively inhibited by puromycin.

An aryl acylamidase from tulip which hydrolyzes 3′,4′-dichloropropionanilide

An aryl acylamidase which hydrolyzes the herbicide propanil (3′,4′-dichloropropionanilide), has been isolated from tulip bulbs and partially purified and characterized. Several chlorinated ring-substituted propionanilide analogs as well as 3,4-dichloroacetanilide and 3′,4′-dichloro-2-methacrylanilide (dicryl) were hydrolyzed by the enzyme. The partially purified enzyme lacked sensitive-SH groups and possessed a broad pH optimum between 6·8 and 7·8. The enzyme was relatively stable up to about 50°, but lost activity rapidly on exposure to temperatures above this. The optimum temperature of assay with 3′,4′-dichloropropionanilide was 53°. The apparent activation energy of the enzyme was 10·3 kcal/mole and the apparent K m was 2·50 × 10 −3m, with 3′,4′-dichloropropionanilide as substrate. The properties of this acylamidase from tulip were compared with aryl acylamidases from rice and liver.

The metabolism of 3,4-dichloropropionanilide in plants. Partial purification and properties of an aryl acylamidase from rice

An aryl acylamidase (aryl-acylamine amidohydrolase, EC 3.5.1.a) from rice, which hydrolyzes 3,4-dichloropropionanilide, has been partially purified and characterized. The distribution of the enzyme in rice and barnyard grass tissues was determined. The enzyme displayed a broad specificity for chlorinated ring-substituted propionanilide analogs, but was specific for 3,4-dichloropropionanalide when compared with several alkyl substituted analogs. The enzyme was inhibited by sulfhydryl reagents and was strongly inhibited at 1·0 × 10 −6 M by the insecticidal carbamates 1-naphthylmethylcarbamate,4-benzothienyl methylcarbamate, 2-chloro-4,5-xylyl methylcarbamate, 2,4,5-trimethylphenyl methylcarbamate, 3,4,5-trimethylphenyl methylcarbamate and 4-(methylthiol) 3,5-xylyl methylcarbamate. The partially purified enzyme had a broad pH optimum between 7·5 and 7·9, with an apparent K m of 2·93 × 10 −3 M for 3,4-dichloropropionanilide. The K i for 1-naphthyl methylcarbamate was 1·51 × 10 −8 M with 3,4-dichloropropionanilide as the substrate. The significance of the enzyme distribution in the resistant and susceptible species and the inhibition of the rice enzyme by insecticidal carbamates is discussed.