Complementation of NADPH oxidase in p67-phox-deficient CGD patients p67-phox/p40-phox interaction.

Eur J Biochem

GREPI, Laboratoire d'Enzymologie, CHU, Grenoble, France; INSERM U. 479, CHU, Bichat, Paris, France.

Published: February 2000

AI Article Synopsis

Article Abstract

Chronic granulomatous disease (CGD) is due to a functional defect of the O2- generating NADPH oxidase of phagocytes. Epstein-Barr-virus-immortalized B lymphocytes express all the constituents of oxidase with activity 100 times less than that of neutrophils. As in neutrophils, oxidase activity of Epstein-Barr-virus-immortalized B lymphocytes was shown to be defective in the different forms of CGD; these cells were used as a model for the complementation studies of two p67-phox-deficient CGD patients. Reconstitution of oxidase activity was performed in vitro by using a heterologous cell-free assay consisting of membrane-suspended or solubilized and purified cytochrome b558 that was associated with cytosol or with the isolated cytosolic-activating factors (p67-phox, p47-phox, p40-phox) from healthy or CGD patients. In p67-phox-deficient CGD patients, two cytosolic factors are deficient or missing: p67-phox and p40-phox. Not more than 20% of oxidase activity was recovered by complementing the cytosol of p67-phox-deficient patients with recombinant p67-phox. On the contrary, a complete restoration of oxidase activity was observed when, instead of cytosol, the cytosolic factors were added in the cell-free assay after isolation in combination with cytochrome b558 purified from neutrophil membrane. Moreover, the simultaneous addition of recombinant p67-phox and recombinant p40-phox reversed the previous complementation in a p40-phox dose-dependent process. These results suggest that in the reconstitution of oxidase activity, p67-phox is the limiting factor; the efficiency of complementation depends on the membrane tissue and the cytosolic environment. In vitro, the transition from the resting to the activated state of oxidase, which results from assembling, requires the dissociation of p40-phox from p67-phox for efficient oxidase activity. In the process, p40-phox could function as a negative regulatory factor and stabilize the resting state.

Download full-text PDF

Source
http://dx.doi.org/10.1046/j.1432-1327.2000.01097.xDOI Listing

Publication Analysis

Top Keywords

oxidase activity
28
cgd patients
16
p67-phox-deficient cgd
12
oxidase
10
nadph oxidase
8
epstein-barr-virus-immortalized lymphocytes
8
reconstitution oxidase
8
cell-free assay
8
cytochrome b558
8
cytosolic factors
8

Similar Publications

Background: Geraniol 10-hydroxylase (G10H) is a cytochrome P450 monooxygenase involved in regulation, which is involved in the biosynthesis of monoterpene. However, G10H is not characterized at the enzymatic mechanism and regulatory function in .

Methods And Results: A gene related to the biosynthesis of monoterpenoid, geraniol 10-hydroxylase, has been cloned from the medicinal plant .

View Article and Find Full Text PDF

CYP2C19 Genotype-Guided Antiplatelet Therapy and Clinical Outcomes in Patients Undergoing a Neurointerventional Procedure.

Clin Transl Sci

January 2025

Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.

In neurovascular settings, including treatment and prevention of ischemic stroke and prevention of thromboembolic complications after percutaneous neurointerventional procedures, dual antiplatelet therapy with a P2Y12 inhibitor and aspirin is the standard of care. Clopidogrel remains the most commonly prescribed P2Y12 inhibitor for neurovascular indications. However, patients carrying CYP2C19 no-function alleles have diminished capacity for inhibition of platelet reactivity due to reduced formation of clopidogrel's active metabolite.

View Article and Find Full Text PDF

Probing the Active Nitrogen Species in Nitrogen-Doped Carbon Nanozymes for Enhanced Oxidase-Like Activity.

Small

January 2025

Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.

Nitrogen doping emerges as a potent approach to enhance the oxidase-like activity of carbon nanozymes. However, the unclear knowledge of the active nitrogen species within nitrogen-doped carbon nanozymes hinders the advancement of high-performance carbon nanozymes. Herein, a group of nitrogen-doped carbon (N/C) nanozymes with controllable nitrogen dopants are successfully synthesized via a dicyandiamide-assisted pyrolysis method.

View Article and Find Full Text PDF

Spodoptera litura (Lepidoptera: Noctuidae) is one of the most destructive insect pests. Insecticides remain the principal management tool to control this pest. However, indiscriminate use of insecticides has resulted in the development of resistance to a variety of insecticides in S.

View Article and Find Full Text PDF

Construing the resilience to osmotic stress using endophytic fungus in maize (Zea mays L.).

Plant Mol Biol

January 2025

Department of Plant Pathology, University of Agricultural Sciences, Gandhi Krishi Vignana Kendra (GKVK), Bengaluru, India.

In a wake of shifting climatic scenarios, plants are frequently forced to undergo a spectrum of abiotic and biotic stresses at various stages of growth, many of which have a detrimental effect on production and survival. Naturally, microbial consortia partner up to boost plant growth and constitute a diversified ecosystem against abiotic stresses. Despite this, little is known pertaining to the interplay between endophytic microbes which release phytohormones and stimulate plant development in stressed environments.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!