Influence of salinity and dissolved organic carbon on acute Cu toxicity to the rotifer Brachionus plicatilis.

Acute copper (Cu) toxicity tests (48-h LC50) using the euryhaline rotifer Brachionus plicatilis were performed to assess the effects of salinity (3, 16, 30 ppt) and dissolved organic carbon (DOC, ∼ 1.1, ∼ 3.1, ∼ 4.

Cofractionation of HMGB proteins with histone dimers.

An effective and flexible method is presented that can be used to investigate cofractionation of groups of nuclear proteins. The method was used to analyze chromatin-related proteins, of which high-mobility group B (HMGB) proteins consistently cofractionated by cation-exchange chromatography with the histone dimer (H2A-H2B). This led to the hypothesis that the two form a complex, further suggested by gel filtration, in which the HMGBs with core histones eluted as a defined high-molecular-weight peak.

Characterization of post-translational modifications of the linker histones H1 and H5 from chicken erythrocytes using mass spectrometry.

Histone linker proteins H1 and H5 were purified from chicken erythrocyte cell nuclei under nondenaturing conditions. The purified linker histones were analyzed using in-solution enzymatic digestions followed by nanoflow reverse-phase high-performance liquid chromatography tandem mass spectrometry. We have identified all six major isoforms of the chicken histone H1 (H101, H102, H103, H110, H11R and H11L) and, in addition, the specialist avian isoform H5.

Surgery for cataract.

Reorganisation of in-house services is an efficient way to improve quality and increase volume

The oxidised histone octamer does not form a H3 disulphide bond.

A H3 dimer band is produced when purified native histone octamers are run on an SDS-PAGE gel in a beta-mercaptoethanol-free environment. To investigate this, native histone octamer crystals, derived from chicken erythrocytes, and of structure (H2A-H2B)-(H4-H3)-(H3'-H4')-(H2B'-H2A'), were grown in 2 M KCl, 1.35 M potassium phosphates and 250-350 microM of the oxidising agent S-nitrosoglutathione, pH 6.

High-resolution structure of the native histone octamer.

Crystals of native histone octamers (H2A-H2B)-(H4-H3)-(H3'-H4')-(H2B'-H2A') from chick erythrocytes in 2 M KCl, 1.35 M potassium phosphate pH 6.9 diffract X-rays to 1.

Histone structures: targets for modifications by molecular assemblies.

The core histone proteins contain modification sites that are key elements in the regulation of the cell cycle, DNA replication and repair with histone assembly, control of gene expression, and transcriptional elongation. Much work has been done on the various molecular assemblies that remodel nucleosomes, methylate, ubiquitinate, and cause ADP-ribosylation of histones, and acetylate and phosphorylate core histone tails. The core histones are the final targets of the enzymes in the molecular assemblies.

Precautions in the use of 110mAg as a tracer of silver metabolism in ecotoxicology: preferential bioconcentration of 109Cd by trout gills after 110mAg exposure.

An often overlooked problem in the use of radiotracers is the possibility of isotopic contamination. Commercially available silver 110mAg was used to study silver uptake and depuration in rainbow trout and European eel. Quality control by means of comparative gamma and beta counting brought our attention to a contamination of the 110mAg stock with 109Cd, which could be seen only because the 109Cd was markedly bioconcentrated by trout gills.