Differential radioactive quantification of protein abundance ratios between benign and malignant prostate tissues: cancer association of annexin A3.

A differential quantitative protein expression study, comparing matched prostate cancerous and benign tissues from 31 patients, revealed proteins newly associated with prostate cancer. Average effects for 17 proteins whose abundance was significantly different (p<0.01) across patients ranged from 1.

Determination of fractional synthesis rates of mouse hepatic proteins via metabolic 13C-labeling, MALDI-TOF MS and analysis of relative isotopologue abundances using average masses.

Proteins of a liver extract taken from a metabolically (13)C-labeled mouse were separated by 2D-PAGE and identified after tryptic digestion by MALDI-TOF MS peptide mass fingerprinting. (13)C-Labeling of proteins was achieved by an infusion of U-(13)C-glucose, which is metabolized to labeled nonessential amino acids. The labeling was analyzed using the relative isotopologue abundances of the measured isotope pattern of tryptic peptides and quantified by their increase in the average molecular mass (DeltaAVM).

Molecular analysis of homocysteic acid-induced neuronal stress.

Hyperhomocysteinemia is a risk factor for vascular and neuronal lesions often observed with concomitant high levels of homocysteic acid. In contrast to homocysteine, homocysteic acid induces calcium influx into neurons, with characteristics of an excitotoxic glutamatergic agonist at elevated concentrations. On the molecular level this is correlated to fast modifications of proteins (phosphorylation and proteolysis).

Proteome analysis reveals a distinct molecular profile of cellular stress following incubation of DDT1-MF2 smooth muscle cells in the presence of a high concentration of hyperforin.

The acylphloroglucinol derivative hyperforin is a major constituent of St. John's wort extracts ( Hypericum perforatum L.), which has been demonstrated to contribute to the antidepressant action of this herbal drug.

Three-beam interference is a sensitive measure of the efficacy of macromolecular refinement techniques.

Triplet phases recorded from insulin crystals were used to measure the improvement of phases during model refinement and to quantify the contribution made by each step in the refinement. Conventional amplitude data were recorded to 1.5 A resolution from rhombohedral pig insulin crystals using 1.

Analysis of relative isotopologue abundances for quantitative profiling of complex protein mixtures labelled with the acrylamide/D3-acrylamide alkylation tag system.

The new method of analysis of relative isotopologue abundances (ARIA) applied here is based on the evaluation of total isotope patterns of tryptic protein fragments measured by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS) to calculate the mixing ratios of composites consisting of stable isotope labelled and isotopically natural (unlabelled) proteins, as described in an accompanying paper in this issue. Recently, Sechi (Rapid Commun. Mass Spectrom.

Protein abundance quantification in embryonic stem cells using incomplete metabolic labelling with 15N amino acids, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry, and analysis of relative isotopologue abundances of peptides.

An isotope dilution method for protein quantification is presented in the context of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS) and mass fingerprinting experiments, revealing an unappreciated high reproducibility and accuracy of relative peak intensity measurements. Labelled proteins were generated by growing cells in a medium containing (15)N-enriched amino acids, and were mixed with proteins of natural isotopic composition from control cells in ratios of approximately 0:1, 1:7, 1:2, 2:1, 7:1, and 1:0 (labelled/unlabelled). Mixtures were separated by two-dimensional gel electrophoresis and analysed by MALDI-TOFMS using typical experimental conditions.