scholarly journals Effect of some thiocarbamate compounds on aldehyde dehydrogenase and implications for the disulfiram ethanol reaction

1991 ◽  
Vol 278 (1) ◽  
pp. 189-192 ◽  
Author(s):  
T M Kitson
Keyword(s):  
Dehydrogenase Activity ◽  
Aldehyde Dehydrogenase ◽  
Esterase Activity ◽  
Negligible Effect ◽  
Weak Inhibitor ◽  
Low Concentration ◽  
The Third ◽  
Sheep Liver ◽  
Physiological Phenomenon

The effects of S-methyl diethyldithiocarbamate, S-methyl diethylmonothiocarbamate and bis(diethylcarbamoyl) disulphide on sheep liver cytoplasmic aldehyde dehydrogenase were investigated in vitro. The first compound has negligible effect. The second one is a weak inhibitor of the esterase activity of the enzyme and a weaker inhibitor of the dehydrogenase activity. A very low concentration of the third compound, however, acts as a potent inactivator of aldehyde dehydrogenase, similar in this respect to disulfiram, although somewhat slower to react. The possible involvement of these compounds in the physiological phenomenon known as the disulfiram ethanol reaction is discussed.

scholarly journals Studies on the interaction between disulfiram and sheep liver cytoplasmic aldehyde dehydrogenase

1978 ◽  
Vol 175 (1) ◽  
pp. 83-90 ◽  
Author(s):  
T M Kitson
Keyword(s):  
Enzyme Activity ◽  
Linear Relationship ◽  
Dehydrogenase Activity ◽  
Aldehyde Dehydrogenase ◽  
Esterase Activity ◽  
Competitive Inhibitor ◽  
Enzyme Molecule ◽  
Covalent Interaction ◽  
Sheep Liver ◽  
Non Linear

The effect of disulfiram, [1-14C]disulfiram and some other thiol reagents on the activity of cytoplasmic aldehyde dehydrogenase from sheep liver was studied. The results are consistent with a rapid covalent interaction between disulfiram and the enzyme, and inconsistent with the notion that disulfiram is a reversible competitive inhibitor of cytoplasmic aldehyde dehydrogenase. There is a non-linear relationship between loss of about 90% of the enzyme activity and amount of disulfiram added; possible reasons for this are discussed. The remaining approx. 10% of activity is relatively insensitive to disulfiram. It is found that modification of only a small number of groups (one to two) per tetrameric enzyme molecule is responsible for the observed loss of activity. The dehydrogenase activity of the enzyme is affected more severely by disulfiram than is the esterase activity. Negatively charged thiol reagents have little or no effect on cytoplasmic aldehyde dehydrogenase. 2,2′-Dithiodipyridine is an activator of the enzyme.

scholarly journals Strawberry Extract as a Tooth Stain Remover

2019 ◽  
Vol 3 (1) ◽  
pp. 28-31
Author(s):  
Ita Yulita ◽  
Ita Astit Karmawati ◽  
Rahaju Budiarti
Keyword(s):  
Treatment Frequency ◽  
Low Concentration ◽  
The Third ◽  
Anterior Teeth ◽  
Intensity Score

This study aimed to compare the effectiveness of strawberry extract with100%, 75%, 50% and 25% concentration in cleaning the extrinsic stain on the teeth. The sample of the study was 32 permanent anterior teeth that were already extracted, consisting of each 16 maxillary and mandibular anterior teeth and all samples have an extrinsic stain. The samples were randomly divided into 4 groups, each group consisting of 8 teeth was treated by applying the strawberry extract with the concentrations of 100%, 75%, 50% and 25%. After 5 minutes, the teeth were rinsed and dried. The study was conducted in vitro for five consecutive days with twice treatment daily. Intensity Score and Extension Score of the stain were measured using the Lobene Stain Index. All samples experienced a decrease in both the Intensity and Extension Scores, the largest decrease in Intensity and Extension Score were obtained from strawberry extracts with concentration of 100%. The significant decrease in the Intensity Score occurs on the third day and continues until the fourth and fifth days, while the significant decrease in the Extention Score occurs on the fourth day and continues until the fifth day. The four group of the strawberry extract concentrations gave a decrease in the score, which distinguishes the treatment frequency. The higher the concentration, the frequency would be less in lowering stain score, whereas at low concentration the decrease of score require more frequency. Keywords: Extrinsic stain, Strawberry extract

scholarly journals Effects of Mg2+, Ca2+ and Mn2+ on sheep liver cytoplasmic aldehyde dehydrogenase

1982 ◽  
Vol 205 (2) ◽  
pp. 443-448 ◽  
Author(s):  
F M Dickinson ◽  
G J Hart
Keyword(s):  
Aldehyde Dehydrogenase ◽  
Esterase Activity ◽  
Metal Ion ◽  
Stopped Flow ◽  
Maximal Effect ◽  
Ion Concentrations ◽  
Sheep Liver ◽  
High Concentrations ◽  
Flow Experiments ◽  
Active Centres

Sheep liver cytoplasmic aldehyde dehydrogenase is strongly inhibited by Mg2+, Ca2+ and Mn2+. The inhibition is only partial, however, with 8-15% of activity remaining at high concentrations of these agents. In 50 mM-Tris/Hcl, pH 7.5, the concentrations giving half-maximal effect were: Mg2+, 6.5 micrometers; Ca2+, 15.2 micrometers; Mn2+, 1.5 micrometer. The esterase activity of the enzyme is not affected by such low metal ion concentrations, but appears to be activated by high concentrations. Fluorescence-titration and stopped-flow experiments provide evidence for interaction of Mg2+ with NADH complexes of the enzyme. As no evidence for the presence of increased concentrations of functioning active centres was obtained in the presence of Mg2+, it is concluded that effects of Mg2+ (and presumably Ca2+ and Mn2+ also) are brought about by trapping increased concentrations of NADH in a Mg2+-containing complex. This complex must liberate products more slowly than any of the complexes involved in the non-inhibited mechanism.

Human Cord Blood Cells with Rapid In Vivo Platelet Regenerating Activity in NOD/SCID-IL-2Rγc-/- Mice Show Variable Aldehyde Dehydrogenase Activity.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2429-2429
Author(s):  
Alice M.S. Cheung ◽  
Connie J. Eaves
Keyword(s):  
Cord Blood ◽  
Dehydrogenase Activity ◽  
Aldehyde Dehydrogenase ◽  
Hematopoietic Cells ◽  
Scid Mice ◽  
Human Cord Blood ◽  
Post Transplant ◽  
Aldehyde Dehydrogenase Activity

Abstract Abstract 2429 Poster Board II-406 Human cord blood (CB) has emerged as an attractive source of hematopoietic cells for patients lacking a suitable donor. However, marked delays in platelet and immune recovery pose significant challenges to the use of CB cells as transplants for either children or adult patients. These difficulties in the use of CB have been attributed to low absolute numbers of repopulating cells (RCs) in most CB units which is not readily overcome by simply combining multiple units. Xenotransplantation of human hematopoietic cells into highly immunodeficient sublethally irradiated NOD/SCID mice has proven to be a powerful approach to characterize different types of primitive human hematopoietic cells with repopulating potential. However, the residual NK activity intrinsic to NOD/SCID mice poses a significant barrier to the engraftment of intermediate types of repopulating human cells and also to the terminal stages of their differentiation, as shown by recent studies using more immunodeficient mice as hosts. Nevertheless, the cells responsible for early platelet recovery post-transplant and factors that regulate their activity remain largely unknown. To address this issue, we have developed a quantitative and sensitive assay for characterizing the phenotypes of human CB cells that regenerate mature platelets detectable in the blood of NOD/SCID-IL-2Rγc-/- mice 3-6 weeks post-transplant. Lineage marker-negative (Lin-) human CB cells were stained with Aldefluor and then those with low light side-scattering properties were further separated by FACS according to whether they displayed aldehyde dehydrogenase activity above (ALDH+) or below (ALDH-) that detected in the presence of an ALDH inhibitor. Assays of different pooled human CB preparations showed that the most primitive class of in vitro megakaryocyte (Mk) colony-forming cells and cells responsible for rapid human platelet production in NOD/SCID-IL-2Rγc-/- mice were variably and comparably distributed between the small ALDH+ and prevalent ALDH- fractions. From 3 experiments, the following values were obtained for the ALDH+ and ALDH- subsets, respectively; ALDH+ - mature CFU-Mk = 47.8±21.3% of the total Lin- fraction, intermediate CFU-Mk = 66.3±25.4%, primitive CFU-Mk = 75.5±14.0%, 3-week platelet-producing STRC = 63.8±12.3%, 6-week platelet-producing STRC = 81.5±5.8%; and ALDH- - mature CFU-Mk = 52.2±21.3% of the total Lin- fraction, intermediate CFU-Mk = 33.7±25.4%, primitive CFU-Mk = 24.5±14.0%, 3-week platelet-producing STRC = 36.2±12.3%, 6-week platelet-producing STRC = 18.5±5.8%. Limiting dilution assays revealed 1 in 830 Lin-ALDH+ CB cells to be a cell that can produce detectable platelets in vivo within 3 weeks (95% CI = 1 in 534 to 1 in 1290) but only 1 in 1996 (95% CI = 1 in 1226 to 1 in 3247) within 6 weeks. The present study demonstrates the feasibility of using NOD/SCID-IL-2Rγc-/- mice for the sensitive detection of human CB cells with in vivo platelet regenerating activity and suggests that these may be closely related to primitive cells with in vitro Mk clonogenic activity (>50 Mk per colony). Biologically important platelet progenitors may thus be heterogeneous with respect to ALDH+ activity. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Identification of a catalytically essential nucleophilic residue in sheep liver cytoplasmic aldehyde dehydrogenase

1991 ◽  
Vol 275 (1) ◽  
pp. 207-210 ◽  
Author(s):  
T M Kitson ◽  
J P Hill ◽  
G G Midwinter
Keyword(s):  
Aldehyde Dehydrogenase ◽  
Esterase Activity ◽  
Tryptic Digestion ◽  
Sheep Liver ◽  
Unequivocal Identification ◽  
Peptide Fractionation

Sheep liver cytoplasmic aldehyde dehydrogenase was labelled by reaction with the substrate p-nitrophenyl di[14C]methylcarbamate. After tryptic digestion and peptide fractionation the labelled residue was identified as Cys-302. This is the first unequivocal identification of the essential enzymic nucleophile in the esterase activity of aldehyde dehydrogenase. By implication, Cys-302 is probably also the residue that is acylated by aldehyde substrates and the first residue that is modified by disulfiram.

Chemical studies of high-Km aldehyde dehydrogenase from rat liver mitochondria

1991 ◽  
Vol 69 (2-3) ◽  
pp. 193-197 ◽  
Author(s):  
C. Stan Tsai ◽  
David J. Senior
Keyword(s):  
Dehydrogenase Activity ◽  
Rat Liver ◽  
Aldehyde Dehydrogenase ◽  
Esterase Activity ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Coenzyme Binding ◽  
High K ◽  
Chemical Studies ◽  
Ionizable Groups

Studies of pH-dependent kinetics implicate two ionizable groups in the dehydrogenase and esterase reactions catalysed by high-Km aldehyde dehydrogenase from rat liver mitochondria. Sensitized photooxidation completely arrests the bifunctional activities of the dehydrogenase. Carboxamidomethylation abolishes the dehydrogenase activity, whereas acetimidination eliminates the esterase activity. These results suggest that histidine (pKa near 6) and cysteine (pKa near 10) are likely the catalytic residues for the dehydrogenase activity, while the esterase activity is functionally related to histidine (pKa near 7) and a residue with the pKa value of 10–11. The two residues, a carboxyl group and an arginine, that discriminate between NAD+ and NADP+ are present at the coenzyme binding site of the mitochondrial high-Km aldehyde dehydrogenase from rat liver.Key words: aldehyde dehydrogenase, rat liver, mitochondria, esterase.

Inhibition of the dehydrogenase activity of sheep liver cytoplasmic aldehyde dehydrogenase by magnesium ions

Biochemistry ◽  
1983 ◽  
Vol 22 (4) ◽  
pp. 776-784 ◽  
Author(s):  
Adrian F. Bennett ◽  
Paul D. Buckley ◽  
Leonard F. Blackwell
Keyword(s):  
Dehydrogenase Activity ◽  
Aldehyde Dehydrogenase ◽  
Magnesium Ions ◽  
Sheep Liver
Sign in / Sign up

Export Citation Format

Share Document