Label-free quantitative proteomics of two Bifidobacterium longum strains.

Bifidobacteria are gram-positive anaerobes with a high Guanine/Cytosine genome content. Specific strains are used as probiotics because of their health benefits. Probiotics are live microorganisms with a positive influence on their host's health.

Combining protein identification and quantification: C-terminal isotope-coded tagging using sulfanilic acid.

Two methods of differential isotopic coding of carboxylic groups have been developed to date. The first approach uses d0- or d3-methanol to convert carboxyl groups into the corresponding methyl esters. The second relies on the incorporation of two 18O atoms into the C-terminal carboxylic group during tryptic digestion of proteins in H(2)18O.

Differentially isotope-coded N-terminal protein sulphonation: combining protein identification and quantification.

Most proteomic labelling technologies intend to improve protein quantification and/or facilitate (de novo) peptide sequencing. We present here a novel stable-isotope labelling method to simultaneously identify and quantify protein components in complex mixtures by specifically derivatizing the N-terminus of proteins with 4-sulphophenyl isothiocyanate (SPITC). Our approach combines protein identification with quantification through differential isotope-coded labelling at the protein N-terminus prior to digestion.

Cystatin C as a potential cerebrospinal fluid marker for the diagnosis of Creutzfeldt-Jakob disease.

The definite diagnosis of Creutzfeldt-Jakob disease (CJD), the most common form of human prion diseases, relies upon neuropathological data usually obtained at autopsy. In living patients, the diagnosis, based on suggestive clinical features and EEG abnormalities, can be aided by the detection of altered levels of isoforms of the 14-3-3 protein in the cerebrospinal fluid (CSF). However, the validity of this test has been recently challenged and the search for other, more reliable biomarkers for CJD remains highly desirable.

Proteomics application exercise of the Swiss Proteomics Society: report of the SPS'02 session.

After the success of the mass spectrometry (MS) round table that was held at the first Swiss Proteomics Society congress (SPS'01) in Geneva, the SPS has organized a proteomics application exercise and allocated a full session at the SPS'02 congress. The main objective was to encourage the exchange of expertise in protein identification, with a focus on the use of mass spectrometry, and to create a bridge between the users' questions and the instrument providers' solutions. Two samples were sent to fifteen interested labs, including academic groups and MS hardware providers.

A potential cerebrospinal fluid and plasmatic marker for the diagnosis of Creutzfeldt-Jakob disease.

The recent occurrence of the new variant of Creutzfeldt-Jakob disease (CJD), probably transmitted to humans by cattle affected by the bovine form of spongiform encephalopathy, has generated renewed interest in the clinical issues related to human spongiform encephalopathies. Using the current set of diagnostic tools, these rare but devastating conditions may be difficult to diagnose with accuracy before death. The objective of the present communication is to describe the discovery of a potential cerebrospinal fluid (CSF) and plasmatic marker of human transmissible spongiform encephalopathies.

Production of the antiviral proteins 2'5'oligoadenylate synthetase, PKR and Mx in interstitial cells and spermatogonia.

We report an in vitro analysis of the spatial pattern of production of three antiviral proteins (2'5'oligoadenylate synthetase, 2'5'AS; double-stranded RNA-activated protein kinase, PKR; and Mx protein, Mx) in the rat testis, in basal conditions and following stimulation with interferon (IFN) or Sendai virus. The two major constituents of interstitial tissue--Leydig cells and macrophages--constitutively produce 2'5' oligoadenylate synthetase (2'5'AS), PKR and Mx. Production of an isoform of 2'5'AS was induced following Leydig cells stimulation by the Sendai virus.