Oxidation of the catalytic cysteine of protein-tyrosine phosphatases (PTP), which leads to their reversible inactivation, has emerged as an important regulatory mechanism linking cellular tyrosine phosphorylation and signalling by reactive-oxygen or -nitrogen species (ROS, RNS). This review focuses on recent findings about the involved pathways, enzymes and biochemical mechanisms. Both the gene...

Protein oxidation mechanisms result in a wide array of modifications, from backbone cleavage or protein crosslinking to more subtle modifications such as side chain oxidations. Protein oxidation occurs as part of normal regulatory processes, as a defence mechanism against oxidative stress, or as a deleterious processes when antioxidant defences are overcome. Because blood is continually exposed...

By postmortem biochemical and molecular genetic analyses, an 8-month-old infant was diagnosed with long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency, an inborn error of mitochondrial fatty acid beta-oxidation. He was born following a pregnancy complicated by a maternal floor infarction of the placenta, a disorder of unknown etiology. We speculate that the child's autosomal recessive ...

An activated sludge process (ASP) is a biochemical process employed for treating sewage and industrial waste-water, which uses microorganisms and air (or oxygen) to biologically oxidize organic pollutants, producing a waste sludge (or floc) containing the oxidized material. The optimal operation of the biological treatment processes is a challenging task because of the stringent effluent requir...

Insufficient oxygen transfer can result in anaerobic biofilms and odor generation during biochemical oxygen demand (BOD) removal in trickling filters, and can limit ammonia oxidation in nitrifying trickling filters. Since oxygen transfer to biofilms in plastic media trickling filters occurs by diffusion of oxygen through thin fluid films, previous models used solutions based on penetration theo...

The majority of protein disulfides in cells is considered an important inert structural, rather than a dynamic regulatory, determinant of protein function. Here, we show that some disulfides in proteins also are regulated by cell redox status with functional consequences. We find that reactive oxygen species (ROS) produced by mitochondria are actively used by cells to facilitate cell-surface pr...

The low enthalpy program developped in the Paris Basin provides the opportunity for studying the gas geochemistry of the calcareous aquifer of the Dogger. Hydrocarbons and C02 are mainly biogenic, He displays high concentrations. He, Ar and N2 have multiple origins (radioactive decay, atmospheric migration, biochemical processes). The distribution of the gases in the zones of the basin varies i...

Metal ions play essential roles in about one third of enzymes [1]. These ions can modify electron flow in a substrate or enzyme, thus effectively controlling an enzyme-catalyzed reaction. They can serve to bind and orient substrate with respect to functional groups in the active site, and they can provide a site for redox activity if the metal has several valence states. Without the appropriate...

Plant organisms possess a complex set of defence mechanisms that are responsible for preventing unfavourable interactions with other living organisms in their natural environment or for reducing negative effects of such interactions. They can be classified into two groups: early responses that occur immediately or shortly after contact with a pathogenic organism, usually in the proximity of the...

Worldwide, metals have been distributed to excessive levels in the environment due to industrial and agricultural activities. Plants growing on soils contaminated with excess levels of metals experience a disturbance of the cellular redox balance, which leads to an augmentation of reactive oxygen species (ROS). Even though the increased ROS levels can cause cellular damage, controlled levels pl...