Activity Determination of 3‐Iodopyridineadenine Dinucleotide and Its Phosphate as Hydride Acceptors in the Presence, of Dehydrogenases Using a Coupled Redox System

Abdallah, Mohamed Abou-Elwafa; Biellmann, Jean‐François

doi:10.1111/j.1432-1033.1980.tb07208.x

Cited by 21 publications

(7 citation statements)

References 13 publications

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“…Although iodopyridine-containing compounds retain their iodine substituent to sufficient degree to permit their use as heavy atom labels for in vitro studies (41), the inertness to dehalogenation of iodopyridines and their in vivo distribution is unknown. When 5-iodonicotinic acid was injected into normal mice, thyroid uptake was less than 0.2% ID at all time points, suggesting minimal loss of iodine from this compound in vivo.…”

Section: Discussionmentioning

confidence: 99%

N-Succinimidyl 5-(trialkylstannyl)-3-pyridinecarboxylates: a new class of reagents for protein radioiodination

Garg¹,

Garg²,

Zalutsky³

1991

Bioconjugate Chem.

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N-Succinimidyl 5-(trialkylstannyl)-3-pyridinecarboxylates (alkyl = Me, Bu) have been prepared and used as a precursor to label N-succinimidyl 5-[131I]iodo-3-pyridinecarboxylate (SIPC). SIPC was obtained in greater than 80% yield from either the methyl or butyl precursor with N-chlorosuccinimide and heating at 60-65 degrees C. Significantly lower yields were observed with tert-butyl hydroperoxide. After a 30-min incubation with [131I]SIPC at pH 8.5, goat IgG, an intact monoclonal antibody (MAb), and a MAb F(ab')2 fragment were labeled in 60-65% yield. Specific binding of the MAb and MAb fragment after SIPC labeling was identical with that observed with N-succinimidyl 3-iodobenzoate and higher than that reported previously for these MAbs after labeling by using the Iodogen method. When 5-[131I]iodonicotinic acid was injected into normal mice, thyroid uptake was less than 0.2% of the injected dose, reflecting the inertness of this compound to deiodination. Paired-label biodistribution studies indicate that for both the MAb and the F(ab')2 labeled by using SIPC, accumulation of activity in the thyroid and other tissues is comparable to that observed when these proteins were labeled by using N-succinimidyl 3-iodobenzoate. The results of this study suggest that SIPC may be a reagent for labeling MAbs with halogen nuclides.

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Section: Discussionmentioning

confidence: 99%

N-Succinimidyl 5-(trialkylstannyl)-3-pyridinecarboxylates: a new class of reagents for protein radioiodination

Garg¹,

Garg²,

Zalutsky³

1991

Bioconjugate Chem.

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“…The methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay was used to determine cell activity as described previously. 32 In brief, cells were washed twice with Krebs-Ringer bicarbonate buffer followed by incubation with 110 μL MTT solution (0.5 mg/mL) for 4 hours at 37°C, 5% CO 2 . After incubation, 90 μL was removed, 100 μL 0.01 N HCl in isopropanol added to each well, and then the plate was gently shaken for 3 minutes.…”

Section: Methodsmentioning

confidence: 99%

In Vivo and In Vitro Arsenic Exposition Induces Oxidative Stress in Anterior Pituitary Gland

et al. 2016

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Inorganic arsenic (iAs) is at the top of toxic metalloids. Inorganic arsenic-contaminated water consumption is one of the greatest environmental health threats worldwide. Human iAs exposure has been associated with cancers of several organs, neurological disorders, and reproductive problems. Nevertheless, there are no reports describing how iAs affects the anterior pituitary gland. The aim of this study was to investigate the mechanisms involved in iAs-mediated anterior pituitary toxicity both in vivo and in vitro. We showed that iAs administration (from 5 to 100 ppm) to male rats through drinking water increased messenger RNA expression of several oxidative stress-responsive genes in the anterior pituitary gland. Serum prolactin levels diminished, whereas luteinizing hormone (LH) levels were only affected at the higher dose tested. In anterior pituitary cells in culture, 25 µmol/L iAs significantly decreased prolactin release in a time-dependent fashion, whereas LH levels remained unaltered. Cell viability was significantly reduced mainly by apoptosis evidenced by morphological and phosphatidylserine externalization studies. This process is characterized by early depolarization of mitochondrial membrane potential and increased levels of reactive oxygen species. Expression of some key oxidative stress-responsive genes, such as heme oxygenase-1 and metallothionein-1, was also stimulated by iAs exposure. The antioxidant N-acetyl cysteine prevented iAs-induced effects on the expression of oxidative stress markers, prolactin release, and apoptosis. In summary, the present work demonstrates for the first time that iAs reduces prolactin release both in vivo and in vitro and induces apoptosis in anterior pituitary cells, possibly resulting from imbalanced cellular redox status.

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“…The routine assay procedure involved the phenazine methosulfate (PMS)-coupled reduction of 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) by the NADPH generated in the enzymatic oxidation of mannitol. This procedure was slightly modified from that reported by Abdallah and Biellmann (1). The assay mixture consisted of: 2.2 ml of 0.5 M mannitol in 50 mM 4-(2-hydroxyethyl)-1piperazine ethanesulfonic acid, Na (HEPES), pH 9; 25 ,ul of 25 mM NADP; 25 ILI of 25 mM PMS; and 200 pul of 5 mM MTT.…”

Section: Methodsmentioning

confidence: 99%

“…The assay mixture consisted of: 2.2 ml of 0.5 M mannitol in 50 mM 4-(2-hydroxyethyl)-1piperazine ethanesulfonic acid, Na (HEPES), pH 9; 25 ,ul of 25 mM NADP; 25 ILI of 25 mM PMS; and 200 pul of 5 mM MTT. Reactions were initiated with enzyme, and the absorbance change was monitored at 578 nm, using an extinction coefficient of 1.5 x 104 M1 cm-1 (1). Assays which include zinc ion as inhibitor were monitored by direct quantitation of the reduction of NADP (see below).…”

Section: Methodsmentioning

confidence: 99%

Purification and characterization of mannitol dehydrogenase from Aspergillus parasiticus

Niehaus¹,

Dilts²

1982

J Bacteriol

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Mannitol dehydrogenase, NADP specific (EC 1.1.1.138), was purified from mycelium of Aspergillus parasiticus (1-11-105 Whl). The enzyme had a molecular weight of 1.4 x 1 and was composed of four subunits of apparently equal size. The substrate specificity was limited to D-mannitol, D-glucitol, D-arabinitol, 1deoxy-D-mannitol, and 1-deoxy-D-glucitol. Zinc ion was a powerful inhibitor of the enzyme, inhibition being competitive with respect to mannitol, with Ki about 1 ,uM. It is proposed that the stimulation of polyketide synthesis by zinc ion may be mediated in part by inhibition of mannitol dehydrogenase.

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Activity Determination of 3‐Iodopyridineadenine Dinucleotide and Its Phosphate as Hydride Acceptors in the Presence, of Dehydrogenases Using a Coupled Redox System

Cited by 21 publications

References 13 publications

N-Succinimidyl 5-(trialkylstannyl)-3-pyridinecarboxylates: a new class of reagents for protein radioiodination

N-Succinimidyl 5-(trialkylstannyl)-3-pyridinecarboxylates: a new class of reagents for protein radioiodination

In Vivo and In Vitro Arsenic Exposition Induces Oxidative Stress in Anterior Pituitary Gland

Purification and characterization of mannitol dehydrogenase from Aspergillus parasiticus

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