Isolation and Expression of Murine Carbonic Anhydrase IV

Hurt, Jonathan D.; Tu, Chingkuang; Laipis, Philip J.

doi:10.1006/prep.1997.0801

Cited by 6 publications

(3 citation statements)

References 55 publications

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“…As Aox reversed an inhibitory effect of a carbonic anhydrase inhibitor, we consider a possible role of some CA isoform as a ROS scavenger. Two candidates for such an antioxidant function could be CA III and IV, the latter because it contains cysteine groups that may participate in redox reactions (Hurt et al 1998), and the former because it behaves as an important ROS scavenger (Raisanen et al 1999) and is present in type I carotid body cells from rat (Yamamoto et al 2003). CA III is a cytoplasmic enzyme with a relatively low affinity for sulphonamide inhibitors (Kararli & Silverman, 1985), while at the same time acetazolamide is only moderately permeable (Holder & Hayes, 1965).…”

Section: Reduction Of the Ahr By Acetazolamide; Reversal By Aoxmentioning

confidence: 99%

“…These two factors, limited permeability of acetazolamide and its low affinity for CA III could then explain why a relatively high dose is needed to completely abolish the hypoxic ventilatory response (Teppema et al 1992). With regard to CA IV, we are not aware of data showing a role of this protein in regulating the (extracellular) redox state, for example by S ‐glutathiolation of one or more of its cysteine residues (Hurt et al 1998). It should also be mentioned that as yet the presence of CA IV in the carotid bodies has not been demonstrated.…”

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confidence: 99%

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Antioxidants reverse depression of the hypoxic ventilatory response by acetazolamide in man

Teppema¹,

Bijl²,

Romberg³

et al. 2006

The Journal of Physiology

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The carbonic anhydrase inhibitor acetazolamide may have both inhibitory and stimulatory effects on breathing. In this placebo-controlled double-blind study we measured the effect of an intravenous dose (4 mg kg −1 ) of this agent on the acute isocapnic hypoxic ventilatory response in 16 healthy volunteers (haemoglobin oxygen saturation 83-85%) and examined whether its inhibitory effects on this response could be reversed by antioxidants (1 g ascorbic acid I.V. and 200 mg α-tocopherol P.O.). The subjects were randomly divided into an antioxidant (Aox) and placebo group. In the Aox group, acetazolamide reduced the mean normocapnic and hypercapnic hypoxic responses by 37% (P < 0.01) and 55% (P < 0.01), respectively, and abolished the O 2 -CO 2 interaction, i.e. the increase in O 2 sensitivity with rising P CO 2 . Antioxidants completely reversed this inhibiting effect on the normocapnic hypoxic response, while in hypercapnia the reversal was partial. In the placebo group, acetazolamide reduced the normo-and hypercapnic hypoxic responses by 33 and 47%, respectively (P < 0.01 versus control in both cases), and also abolished the O 2 -CO 2 interaction. Placebo failed to reverse these inhibitory effects of acetazolamide in this group. We hypothesize that either an isoform of carbonic anhydrase may be involved in the regulation of the redox state in the carotid bodies or that acetazolamide and antioxidants exert independent effects on oxygen-sensing cells, in which both carbonic anhydrase and potassium channels may be involved. The novel findings of this study may have clinical implications, for example with regard to a combined use of acetazolamide and antioxidants at high altitude.

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Section: Reduction Of the Ahr By Acetazolamide; Reversal By Aoxmentioning

confidence: 99%

mentioning

confidence: 99%

Antioxidants reverse depression of the hypoxic ventilatory response by acetazolamide in man

Teppema¹,

Bijl²,

Romberg³

et al. 2006

The Journal of Physiology

View full text Add to dashboard Cite

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“…The pellets were washed and resuspended in denaturing buffer [5.6 M guanidine hydrochloride, 100 mM Tris-HCl, pH8.0, 1 mM EDTA and 1 mM dithiothreitol (DTT) dissolved in degassed sterile H2O] by gentle agitation for 6-16 h at 4oC. The solubilized protein was rapidly diluted 1:25 into degassed refolding buffer [final concentrations: 100 mM Tris-HCl, pH 8.0, 1m M EDTA, 40 mM DTT, 1mM ZnCl 2 , 280 mM guanidine hydrochloride, 500 mM L-arginine, 2 mM glutathione (GSH), 1 mM glutathione disulfide (GSSG)] and allowed to refold for 24 h at 4 o C [23]. The sample was concentrated and desalted by ultrafiltration with a 1K Mini-Ultrasette system (Pall Gelman, USA).…”

Section: Large-scale Expression and Purification Of Recombi-nant Aaitmentioning

confidence: 99%

Recombinant scorpion insectotoxin AaIT kills specifically insect cells but not human cells

Liu

et al. 2002

Cell Res

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The nucleotide sequence deduced from the amino acid sequence of the scorpion insectotoxin AaIT was chemically synthesized and was expressed in Escherichia coli. The authenticity of this in vitro expressed peptide was confirmed by N-terminal peptide sequencing. Two groups of bioassays, artificial diet incorporation assay and contact insecticidal effect assay, were carried out separately to verify the toxicity of this recombinant toxin. At the end of a 24 h experimental period, more than 60% of the testing diamondback moth (Plutella xylostella) larvae were killed in both groups with LC50 value of 18.4 microM and 0.70 microM respectively. Cytotoxicity assay using cultured Sf9 insect cells and MCF-7 human cells demonstrated that the toxin AaIT had specific toxicity against insect cells but not human cells. Only 0.13 microM recombinant toxin was needed to kill 50% of cultured insect cells while as much as 1.3 microM toxin had absolutely no effect on human cells. Insect cells produced obvious intrusions from their plasma membrane before broken up. We infer that toxin AaIT bind to a putative sodium channel in these insect cells and open the channel persistently, which would result in Na+ influx and finally cause destruction of insect cells.

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Selective expression of Kir6.1 protein in different vascular and non-vascular tissues

Sun

Cao

Yang

et al. 2004

Biochemical Pharmacology

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Isolation and Expression of Murine Carbonic Anhydrase IV

Cited by 6 publications

References 55 publications

Antioxidants reverse depression of the hypoxic ventilatory response by acetazolamide in man

Antioxidants reverse depression of the hypoxic ventilatory response by acetazolamide in man

Recombinant scorpion insectotoxin AaIT kills specifically insect cells but not human cells

Selective expression of Kir6.1 protein in different vascular and non-vascular tissues

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