scholarly journals Inhibition of δ-aminolevulinic acid dehydratase activity by cadmium in excised etiolated maize leaf segments during greening

2011 ◽  
Vol 57 (No. 7) ◽  
pp. 332-337 ◽  
Author(s):  
J. Sarangthem ◽  
M. Jain ◽  
R. Gadre
Keyword(s):  
Enzyme Activity ◽  
Aminolevulinic Acid ◽  
Substantial Reduction ◽  
Competitive Inhibitor ◽  
Cd Accumulation ◽  
Nitrogenous Compounds ◽  
Acid Dehydratase ◽  
Alad Activity ◽  
Maize Leaves ◽  
Dehydratase Activity

Supply of 0.1&ndash;0.5 mmol CdCl<sub>2</sub> inhibited &delta;-aminolevulinic acid dehydratase (EC 4.2.1.24, ALAD) activity and total chlorophylls in excised etiolated segments of maize leaves during greening. Due to cadmium supply &delta;-aminolevulinic acid (ALA) content was reduced significantly at 0.5 mmol Cd only. Also the Cd treatment decreased the protein content and accumulated significantly the Cd in the tissue. Significant correlation between Cd accumulation in the leaves and various parameters measured is observed, with the R-squared values being 0.727 with ALAD activity, 0.885 with ALA content, 0.902 with total chlorophylls and 1.00 with proteins. The % inhibition of ALAD activity by Cd was decreased in the presence of nitrogenous compounds, glutamine and NH<sub>4</sub>NO<sub>3</sub> and the observed inhibition was 25% and 16%, respectively. More substantial reduction in % inhibition of enzyme activity by Cd was observed during treatment with glutathione, a ubiquitous thiol and levulinic acid, a competitive inhibitor of ALAD, with the inhibition being only 2% and 4%, respectively. Supply of some essential metal ions, such as Mg, Zn, and Mn, also reduced the % inhibition of enzyme activity by Cd. Inclusion of varying concentrations of ALA during assay also affected the % inhibition of enzyme activity by Cd showing an increased inhibition from 17% to 53% with increasing ALA concentration. It is suggested that Cd inhibits ALAD activity by affecting the ALA binding to the enzyme and/or disrupting thiol interaction.

scholarly journals 5-Aminolevulinic acid dehydratase deficiency porphyria: a twenty-year clinical and biochemical follow-up

1998 ◽  
Vol 44 (9) ◽  
pp. 1892-1896 ◽  
Author(s):  
Ulrich Gross ◽  
Shigeru Sassa ◽  
Karl Jacob ◽  
Jean-Charles Deybach ◽  
Yves Nordmann ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Reference Values ◽  
Aminolevulinic Acid ◽  
Compound Heterozygous ◽  
Acid Dehydratase ◽  
Heme Arginate ◽  
Alad Activity ◽  
Rate Limiting ◽  
Acute Crisis

Abstract 5-Aminolevulinic acid dehydratase (ALAD) activity in two patients with compound heterozygous 5-aminolevulinic acid dehydratase deficiency porphyria was studied over the last 20 years. The patients’ enzyme activity was &lt;10% from 1977 to 1997. An acute crisis in each patient was successfully treated by infusion of glucose and heme arginate. After this therapy both urinary 5-aminolevulinic acid (ALA) and total porphyrins were diminished to 65% in patient B. In patient H, ALA was decreased to 80%, and total porphyrins were reduced to 15% after treatment with heme arginate and glucose. The patients remained free of symptoms after this therapy. Family studies of patient B showed cross-reactive immunological material (CRIM), in which the maternal mutation is CRIM(+), whereas the paternal mutation is CRIM(−). Incubation of erythrocyte lysates with ALA decreased porphyrin formation, whereas incubation with porphobilinogen produced porphyrin concentrations within reference values in both patients, confirming that ALAD activity is rate-limiting in these cells.

scholarly journals Use of Generalized Additive Model to Detect the Threshold of δ-Aminolevulinic Acid Dehydratase Activity Reduced by Lead Exposure

2020 ◽  
Vol 17 (16) ◽  
pp. 5712
Author(s):  
Chan-Ching Huang ◽  
Chen-Cheng Yang ◽  
Te-Yu Liu ◽  
Chia-Yen Dai ◽  
Chao-Ling Wang ◽  
...  
Keyword(s):  
Lead Exposure ◽  
Aminolevulinic Acid ◽  
Lead Level ◽  
Blood Lead ◽  
Additive Models ◽  
Acid Dehydratase ◽  
Alad Activity ◽  
Exposed Workers ◽  
Lead Workers ◽  
Dehydratase Activity

Background: Lead inhibits the enzymes in heme biosynthesis, mainly reducing δ-aminolevulinic acid dehydratase (ALAD) activity, which could be an available biomarker. The aim of this study was to detect the threshold of δ-aminolevulinic acid dehydratase activity reduced by lead exposure. Methods: We collected data on 121 lead workers and 117 non-exposed workers when annual health examinations were performed. ALAD activity was determined by the standardized method of the European Community. ALAD G177C (rs1800435) genotyping was conducted using the polymerase chain reaction and restricted fragment length polymorphism (PCR-RFLP) method. In order to find a threshold effect, we used generalized additive models (GAMs) and scatter plots with smoothing curves, in addition to multiple regression methods. Results: There were 229 ALAD1-1 homozygotes and 9 ALAD1-2 heterozygotes identified, and no ALAD2-2 homozygotes. Lead workers had significantly lower ALAD activity than non-exposed workers (41.6 ± 22.1 vs. 63.3 ± 14.0 U/L, p < 0.001). The results of multiple regressions showed that the blood lead level (BLL) was an important factor inversely associated with ALAD activity. The possible threshold of BLL affecting ALAD activity was around 5 μg/dL. Conclusions: ALAD activity was inhibited by blood lead at a possible threshold of 5 μg/dL, which suggests that ALAD activity could be used as an indicator for lead exposure regulation.

scholarly journals Towards Initial Indications for a Thiol-Based Redox Control of Arabidopsis 5-Aminolevulinic Acid Dehydratase

Antioxidants ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 152 ◽  
Author(s):  
Daniel Wittmann ◽  
Sigri Kløve ◽  
Peng Wang ◽  
Bernhard Grimm
Keyword(s):  
Aminolevulinic Acid ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Thioredoxin Reductase ◽  
Reducing Power ◽  
Reduced Form ◽  
Redox Control ◽  
In Planta ◽  
Acid Dehydratase ◽  
Reducing Conditions ◽  
Alad Activity

Thiol-based redox control is one of the important posttranslational mechanisms of the tetrapyrrole biosynthesis pathway. Many enzymes of the pathway have been shown to interact with thioredoxin (TRX) and Nicotinamide adenine dinucleotide phosphate (NADPH)-dependent thioredoxin reductase C (NTRC). We examined the redox-dependency of 5-aminolevulinic acid dehydratase (ALAD), which catalyzed the conjugation of two 5-aminolevulinic acid (ALA) molecules to porphobilinogen. ALAD interacted with TRX f, TRX m and NTRC in chloroplasts. Consequently, less ALAD protein accumulated in the trx f1, ntrc and trx f1/ntrc mutants compared to wild-type control resulting in decreased ALAD activity. In a polyacrylamide gel under non-reducing conditions, ALAD monomers turned out to be present in reduced and two oxidized forms. The reduced and oxidized forms of ALAD differed in their catalytic activity. The addition of TRX stimulated ALAD activity. From our results it was concluded that (i) deficiency of the reducing power mainly affected the in planta stability of ALAD; and (ii) the reduced form of ALAD displayed increased enzymatic activity.

scholarly journals Erythrocyte D -Aminolevulinic Acid Dehydratase (Ala-D) Activity and Blood Lead Level (Pb-B) of Tortoise (Testudo Hemanni, Gmel.) of Vicinity of Lead and Zinc Smelter “Trepca” in Kosova

1998 ◽  
Vol 1 (1) ◽  
pp. 24-25
Author(s):  
I. Elezaj ◽  
D.A. Rozhaja
Keyword(s):  
Aminolevulinic Acid ◽  
Lead Level ◽  
Blood Lead ◽  
Significant Negative Correlation ◽  
Polluted Environment ◽  
Zinc Smelter ◽  
Acid Dehydratase ◽  
Lead And Zinc ◽  
Testudo Hermanni ◽  
Dehydratase Activity

In comparison with control animals, a significant negative correlation (r = 0.77 -), between lead level and the activity of daminolevulinic acid dehydratase activity in the blood of land turtle (Testudo hermanni, Gmel.) caught in five different localities from heavy polluted environment of lead and zinc smelter “Trepca” was found. The concentration ratio of lead level in blood between control animals and those from the vicinity of smelter was 10:160 % and ratio of ALA-D activity was 10:18,3 U/LE.

New Method for Determination of Aminolaevulinate Dehydratase Activity of Human Erythrocytes as an Index of Lead Exposure

1974 ◽  
Vol 20 (10) ◽  
pp. 1287-1291 ◽  
Author(s):  
Katsumaro Tomokuni
Keyword(s):  
Enzyme Activity ◽  
Ion Exchange ◽  
Present Method ◽  
Aminolevulinic Acid ◽  
Usual Method ◽  
Human Erythrocytes ◽  
New Method ◽  
Ion Exchange Column ◽  
Dehydratase Activity

Abstract I describe a new method for measurement of aminolaevulinate dehydratase (EC 4.2.1.24) activity of human erythrocytes. In this method, the amount of substrate δ-aminolevulinic acid consumed (instead of the amount of porphobilinogen formed) is determined colorimetrically. In the incubation mixture, the δ-aminolevulinic acidpyrrole produced by the condensation of δ-aminolevulinic acid with ethyl acetoacetate is separated from porphobilinogen by extraction with ethyl acetate, without resorting to ion-exchange column chromatography. The pyrrole-containing extract is treated with a modified Ehrlich's reagent. Activity of the enzyme is expressed as micromoles of δ-aminolevulinic acid consumed per minute per liter of erythrocytes. Enzyme activity is more accurately estimated by the present method than by the usual method in which porphobilinogen is measured.

Sign in / Sign up

Export Citation Format

Share Document