Search results for "Biochemistry"

2018

ABC (ATP binding cassette) transporters, ubiquitous in all kingdoms of life, carry out essential substrate transport reactions across cell membranes. Their transmembrane domains bind and translocate substrates and are connected to a pair of nucleotide binding domains, which bind and hydrolyze ATP to energize import or export of substrates. Over four decades of investigations into ABC transporters have revealed numerous details from atomic-level structural insights to their functional and physiological roles. Despite all these advances, a comprehensive understanding of the mechanistic principles of ABC transporter function remains elusive. The human multidrug resistance transporter ABCB1, al…

Echovirus 1 internalization negatively regulates epidermal growth factor receptor downregulation

2016

We have demonstrated previously that the human picornavirus Echovirus 1 (EV1) triggers an infectious internalization pathway that follows closely, but seems to stay separate, from the epidermal growth factor receptor (EGFR) pathway triggered by epidermal growth factor (EGF). Here, we confirmed by using live and confocal microscopy that EGFR and EV1 vesicles are following intimately each other but are distinct entities with different degradation kinetics. We show here that despite being sorted to different pathways and located in distinct endosomes, EV1 inhibits EGFR downregulation. Simultaneous treatment with EV1 and EGF led to an accumulation of EGFR in cytoplasmic endosomes, which was evi…

Environmental aircraft noise aggravates oxidative DNA damage, granulocyte oxidative burst and nitrate resistance inOgg1–/–mice

2020

Background: Large epidemiological studies point towards a link between the incidence of arterial hypertension, ischaemic heart disease, metabolic disease and exposure to traffic noise, supporting t...

Inter- and intraspecific variability in invertebrate acute toxicity response to Arsenic and Fluoride exposure

2018

The adverse effects of arsenic and fluoride exposure on six groups of freshwater invertebrates were investigated. Acute toxicity tests (48-h) with arsenic trioxide (As2NO3) resulted in the following pattern of sensitivity: Daphnia magna 24-h-old = Brachionus patulus 72-h-old = Daphnia. cf. prolata, 21-d-old = D. magna 5-d-old > Heterocypris incongruens juvenile instars > Culex sp. Heterocypris juv. incongruens instars were the second group more tolerant to arsenic and the second group that bioconcentrates arsenic the least. In contrast, invertebrates exposed to sodium fluoride (NaF), showed a different pattern of sensitivity: H. incongruens instars > B. patulus = D. magna 24-h-old > D. cf. …

Out of a creative jumble of ideas in the middle of last Century: Wiener, interdisciplinarity, and all that

2015

Is Biophysics an interdisciplinary science? In order to answer this rhetorical question, it can be useful to look back at history of disciplines, as well as that of the scientific institutions helping their development. In this contribution some aspects of the unusual hodgepodge of concepts involving Biophysics, the legacy of Cybernetics, cognitive science and the central figure of Norbert Wiener are presented and discussed.

Generation of oxysterols formed by free radicals and enzymes by electrochemical oxidation

2016

International audience; It is commonly accepted that cholesterol oxide derivatives, also named oxysterols, are 27 carbon-atom molecules deriving either from enzymatic and non-enzymatic oxidation of cholesterol. Most of these compounds can be synthesized by more or less difficult and time consuming chemical reactions, and some of them have been discovered before the identification of the enzymes [mainly cytochrome P450 enzymes (CYP enzymes)] involved in their biosynthesis. A wide range of biological activities depends on oxysterols. Some oxysterols are also involved in the synthesis of cholesterol metabolites which have various properties. The paper by Weber et al. in this issue of European …

"The human use of human beings": Interdisciplinarity, transdisciplinarity and all that in biophysics and beyond.

2017

Abstract Biophysics, just by looking at its name, indicates an interdisciplinary scientific activity, although the notion of interdisciplinarity, as such, seems to be not widely or specifically discussed by biophysicists. The same seems to have happened as well in the early stages of the development of cybernetics, notably in Norbert Wiener's writings. This situation seems to contrast with what has happened in subsequent developments of cybernetics ideas, notably in general system theory and cognitive sciences. After a few general reflections on the notion of interdisciplinarity, its sophisticated variants and the path leading to the birth of cognitive science, we shall refer to Wiener's th…

Cellular Concentrations of the Transporters DctA and DcuB and the Sensor DcuS of Escherichia coli and the Contributions of Free and Complexed DcuS to…

2017

ABSTRACT In Escherichia coli , the catabolism of C 4 -dicarboxylates is regulated by the DcuS-DcuR two-component system. The functional state of the sensor kinase DcuS is controlled by C 4 -dicarboxylates (like fumarate) and complexation with the C 4 -dicarboxylate transporters DctA and DcuB, respectively. Free DcuS (DcuS F ) is known to be constantly active even in the absence of fumarate, whereas the DcuB-DcuS and DctA-DcuS complexes require fumarate for activation. To elucidate the impact of the transporters on the functional state of DcuS and the concentrations of DcuS F and DcuB-DcuS (or DctA-DcuS), the absolute levels of DcuS, DcuB, and DctA were determined in aerobically or anaerobic…

Bioprospecting challenges in unusual environments

2017

Editorial: The microbiome as a source of new enterprises and job creation.

Effect of heating method on the microbial levels and acrylamide in corn grits and subsequent use as functional ingredient for bread making

2018

Abstract Cereal by-products represent abundant and low-cost resources of nutrients. The study is dedicated to the development of a rapid method for the treatment of corn grits to obtain value added ingredients for breadmaking. The infrared irradiation (IR) at 76 °C and 90 °C and vacuum microwave (VM) heating at 60 °C have been applied for stabilization of corn grits. The corn grit particles were fractionated by size and it was found that the particle size fraction significantly (p