Search results for "Intracellular"
showing 10 items of 821 documents
Proteins and enzymes of the peroxisomal membrane in mammals.
1993
Proteins of the peroxisomal membrane can be schematically divided into two groups, one being made up of more or less characterized proteins with generally unknown functions and the other consisting of enzyme activities of which the corresponding proteins have not been characterized. In the present report, these proteins and enzymes are described with the addition of unpublished results regarding their induction by peroxisome proliferators at the post-transcriptional level. Integral membrane proteins (IMPs) can be isolated using an alkaline solution of sodium carbonate. A dozen of preponderant IMPs can be seen on sodium dodecyl sulfate polyacrylamide gel electrophoresis, and the major band c…
Comment on “Local impermeant anions establish the neuronal chloride concentration”
2014
Glykys et al . (Reports, 7 February 2014, p. 670) proposed that cytoplasmic impermeant anions and polyanionic extracellular matrix glycoproteins establish the local neuronal intracellular chloride concentration, [Cl – ] i , and thereby the polarity of γ-aminobutyric acid type A (GABA A ) receptor signaling. The experimental procedures and results in this study are insufficient to support these conclusions. Contradictory results previously published by these authors and other laboratories are not referred to.
The Role of Mitochondrial Reactive Oxygen Species Formation for Age-Induced Vascular Dysfunction
2010
Aging is an important risk factor for the development of cardiovascular diseases, which can be accelerated by atherosclerosis, diabetes, hypercholesterolemia, or obesity. Vascular aging is mainly characterized by endothelial dysfunction, an alteration of endothelium-dependent signaling processes, and vascular remodeling. The underlying mechanisms include increased production of reactive oxygen species (ROS), inactivation of nitric oxide (•NO), and subsequent formation of reactive nitrogen and oxygen species (RNOS). Elevated RNOS may exhibit new messenger functions by posttranslational oxidative modification of intracellular regulatory proteins or lead to irreversible alterations of biologic…
Electrochemical sensor for evaluating oxidative stress in airway epithelial cells
2021
Cigarette smoke exposure induces oxidative stress within the airways. Increased oxidative burden contributes to the pathogenesis of chronic lung disorders and is associated with aging and chronic inflammation. Airway epithelial cells highly contribute to Reactive Oxygen Species (ROS) generation within injured and inflamed lung tissues. Among ROS, hydrogen peroxide (H2O2) can be monitored in the extracellular space. Herein, we present an amperometric/voltammetric sensor based on gold nanoparticles and graphene oxide able to detect H2O2 with good sensitivity and selectivity. Using this sensor, H2O2 release was measured in conditioned medium from primary bronchial epithelial cells (PBEC), bron…
Plant-growth-regulating phosphono peptides
1990
Phosphono peptides exhibited plant‐growth‐regulating activity when tested on Lepidium sativum and Cucumis sativus. The studies have provided evidence that the mechanism of action of these compounds may involve the uptake of the phosphono peptides into the plant, intracellular hydrolysis of the peptide bond and release of the P‐terminal aminoalkylphosphonic acid. This acid or its metabolite is then probably responsible for the observed physiological effect.
Mannosyl transferases inSaccharomyces cerevisiae: Evidence for the occurrence of ectomannosyltransferase activity
1981
The subcellular distribution of mannosyltransferases inSaccharomyces cerevisiae was studied following the separation of the plasma membrane from other intracellular membranous systems. Most of the activity was linked to internal membranes, and the rest was located at the level of the plasma membrane. Yeast plasma membranes coated on their external face with concanavalin A when incubated with GDP-[U-14C]mannose incorporated 20% less [U-14C]mannose in glycoproteins and 110% more in glycolipids than plasma membranes alone. This suggested that part of the total mannosyltransferase activity of the plasma membrane is located on its outer surface. A significant incorporation of radioactive mannose…
The comparative behavior of Lactococcus lactis in free and immobilized culture processes
1998
This study presents the changes in the physiological state of Lactococcus lactis in different actively growing systems. The intracellular pH (pHin), NADH/NAD ratio and lactate dehydrogenase (LDH) activity were measured in free cell batch culture with or without external pH (pHout) control, and in continuous free or immobilized cell reactors. In free cell batch culture it has been shown that the pHin is dependent both on pHout and age of the culture, while in free cell continuous culture the pHin and the pHout are close together. The NADH/NAD ratio varied inversely with the growth rate, which was related to the changes in the metabolic activities in lactococci. The specificity of the immobil…
Locust flight metabolism studied in vivo by 31P NMR spectroscopy
1991
Flight metabolism of locusts has been extensively studied, but biochemical and physiological methods have led to conflicting results. For this reason the non-invasive and non-destructive method of 31P NMR spectroscopy was used to study migratory locusts, Locusta migratoria, at rest and during flight. 1. In the flight muscle of resting locusts the ratio of phosphoarginine to ATP was the same whether determined by NMR (1.76) or biochemically, but the NMR-visible content of inorganic phosphate (Pi) was only 40% of ATP, i.e., much lower than total Pi as determined biochemically. This suggests that most of the Pi in flight muscle is not free, and hence not available as substrate or effector for …
Role of the Well-Known Basic and Recently Discovered Acidic Glutathione S-Transferases in the Control of Genotoxic Metabolites
1991
Glutathione S-transferases (GSTs; E.C. 2. 5. 1. 18) are a family of enzymes which have increasingly attracted the interest of toxicologists, pharmacologists, biochemists and clinicians since their discovery in 1961 (1). Initially, GSTs were believed to serve as intracellular transport proteins for endogenous compounds with limited solubility in water, thus acting as an intracellular equivalent to albumin in blood plasma. In this assumed capacity of reversible binding and transport of various ligands, the corresponding protein was named ligandin (2). Following the discovery of abundant GST occurrence in most forms of aerobic life including plants, and the GST-catalysed conjugation of a wide …
Oxygen Radical Scavengers
2010
The myocardium can tolerate only relatively short periods of total myocardial ischemia without myocardial cell death. Following short ischemic periods, ischemic damage is reversible by reperfusion. However, with increasing duration and severity of ischemia, the damage inflicted to cardiomyocytes following reperfusion becomes irreversible. The combined pathologic events in the myocardium that follow a critical period of ischemia and leading to either reversible or irreversible damage to both cardiomyocytes and cardiac microvasculature is known as ischemia-reperfusion injury (Goldhaber and Weiss 1992).