Molecular characterisation of atypical BSE prions by mass spectrometry and changes following transmission to sheep and transgenic mouse models.

The prion hypothesis proposes a causal relationship between the misfolded prion protein (PrPSc) molecular entity and the disease transmissible spongiform encephalopathy (TSE). Variations in the conformation of PrPSc are associated with different forms of TSE and different risks to animal and human health. Since the discovery of atypical forms of bovine spongiform encephalopathy (BSE) in 2003, scientists have progressed the molecular characterisation of the associated PrPSc in order to better understand these risks, both in cattle as the natural host and following experimental transmission to other species.

Identification of temperature regulated factors of and their potential roles in virulence.

is the major cause of bacterial gastroenteritis in man, while it is generally regarded as a commensal of the avian gut. Consumption and handling of contaminated poultry meat products are major risk factors for human infection. The body temperature in man (37 °C) and chickens (42 °C) differ markedly, and differential gene regulation and protein expression at different temperatures may in part explain the behaviour in the two hosts.

Pyroglutamyl-N-terminal prion protein fragments in sheep brain following the development of transmissible spongiform encephalopathies.

Protein misfolding, protein aggregation and disruption to cellular proteostasis are key processes in the propagation of disease and, in some progressive neurodegenerative diseases of the central nervous system, the misfolded protein can act as a self-replicating template or prion converting its normal isoform into a misfolded copy of itself. We have investigated the sheep transmissible spongiform encephalopathy, scrapie, and developed a multiple selected reaction monitoring (mSRM) mass spectrometry assay to quantify brain peptides representing the "ragged" N-terminus and the core of ovine prion protein (PrP(Sc)) by using Q-Tof mass spectrometry. This allowed us to identify pyroglutamylated N-terminal fragments of PrP(Sc) at residues 86, 95 and 101, and establish that these fragments were likely to be the result of in vivo processes.

Immunoproteomic characterisation of Mycoplasma mycoides subspecies capri by mass spectrometry analysis of two-dimensional electrophoresis spots and western blot.

Objectives: Mycoplasma mycoides subspecies capri is one of the causative agents of contagious agalactia in goats. The disease is characterised by mastitis, pneumonia, arthritis, keratitis and in acute cases septicaemia. No vaccine is currently available that has been demonstrated to prevent disease.

Metaproteomics analysis reveals the adaptation process for the chicken gut microbiota.

The animal gastrointestinal tract houses a large microbial community, the gut microbiota, that confers many benefits to its host, such as protection from pathogens and provision of essential metabolites. Metagenomic approaches have defined the chicken fecal microbiota in other studies, but here, we wished to assess the correlation between the metagenome and the bacterial proteome in order to better understand the healthy chicken gut microbiota. Here, we performed high-throughput sequencing of 16S rRNA gene amplicons and metaproteomics analysis of fecal samples to determine microbial gut composition and protein expression.

Quantitative profiling of PrP(Sc) peptides by high-performance liquid chromatography mass spectrometry to investigate the diversity of prions.

Prions are proteins that can exist in two (or more) folding states, a normal or cellular form and a series of infectious or prion forms, which are prone to aggregate. The prion form can induce conversion of the cellular form and so transmit phenotypic effects of this structural rearrangement within and between cells and organisms. The conversion of PrP(C), the mammalian prion glycoprotein, to its prion form, PrP(Sc), in the brain is a precursor to progressive neurological degeneration, and the various folded forms of PrP(Sc) (defined by the size and glycosylation of protease-resistant core peptides of the PrP aggregates, PrP(res)) are characteristic of a particular neurodegenerative phenotype or prion disease.

All major prion types recognised by a multiplex immunofluorometric assay for disease screening and confirmation in sheep.

Prion diseases or transmissible spongiform encephalopathies (TSEs) in small ruminants are presented in many forms: classical scrapie, Nor98/atypical scrapie, CH1641 scrapie and bovine spongiform encephalopathy (BSE). We previously described a multiplex immunofluorometric assay (mIFMA), based on a bead array flow cytometry technology, which provided, in a single assay, discrimination between BSE (in cattle and sheep) and classical scrapie (Tang et al., 2010).

Repeated intake of broccoli does not lead to higher plasma levels of sulforaphane in human volunteers.

The plasma pharmacokinetic characteristics of the chemopreventive isothiocyanate sulforaphane were determined in six human volunteers following single and repeated intake of raw broccoli. Initially, an analytical method utilising LC-MS/MS, capable of determining low levels of sulforaphane in human plasma was developed and validated. The plasma profile of the isothiocyanate best fitted a two-compartment pharmacokinetic model.

High-resolution differentiation of transmissible spongiform encephalopathy strains by quantitative N-terminal amino acid profiling (N-TAAP) of PK-digested abnormal prion protein.

New forms of transmissible spongiform encephalopathy (TSE) continue to be identified, and consequently sensitive differential diagnosis is increasingly important both for the management of disease in humans and livestock and in providing confidence in the safety of the food chain. TSE diseases are associated with accumulation of protease-resistant prion protein (PrP(Sc)) and detection of this marker protein is central to diagnosis. Proteolysis by proteinase K (PK) generates protease-resistant products (PrP(res)) with partially variable N-termini.

Absolute bioavailability and dose-dependent pharmacokinetic behaviour of dietary doses of the chemopreventive isothiocyanate sulforaphane in rat.

Sulforaphane is a naturally occurring isothiocyanate with promising chemopreventive activity. An analytical method, utilising liquid chromatography-MS/MS, which allows the determination of sulforaphane in small volumes of rat plasma following exposure to low dietary doses, was developed and validated, and employed to determine its absolute bioavailability and pharmacokinetic characteristics. Rats were treated with either a single intravenous dose of sulforaphane (2.