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Peter Jackson

Publications and source records attributed to Peter Jackson.

8 recordsLinked to original sources
PubMed2006

Analysis of the dynamic Bacillus subtilis Ser/Thr/Tyr phosphoproteome implicated in a wide variety of cellular processes.

The physiological role of proteins phosphorylated on serine/threonine/tyrosine (Ser/Thr/Tyr) residues or the identity of the corresponding kinases and phosphatases is generally poorly understood in bacteria. As a first step in analysing the importance of such phosphorylation, we sought to establish the nature of the Ser/Thr/Tyr phosphoproteome in Bacillus subtilis, using in vivo labelling with [(32)P]-orthophosphate, one-unit pH 2-DE, combined with MS. Highly reproducible 2-D profiles of phosphoproteins were obtained with early stationary-phase cells. The 2-D profiles contained at least 80 clearly labelled spots in the pH range 4-7. Forty-six spots were analysed by MS (confirmed in most cases by LC-MS/MS), identifying a total of 29 different proteins, with 19 identified for the first time as bacterial phosphoproteins. These phosphoproteins are implicated in a wide variety of cellular processes, including carbon and energy metabolism, transport, stress and development. Significant changes to the profiles were obtained as a result of cold, heat or osmotic shock, demonstrating that, in stationary-phase cells, the phosphoproteome is dynamic. An initial comparative study indicated that at least 25 [(32)P]-labelled spots were also stained by Pro-Q Diamond, with apparently six additional phosphoproteins uniquely detected by Pro-Q.

Bacillus subtilis↗
PubMed2005

Performance validation of an improved Xenon-arc lamp-based CCD camera system for multispectral imaging in proteomics.

Advances in gel-based nonradioactive protein expression and PTM detection using fluorophores has served as the impetus for developing analytical instrumentation with improved imaging capabilities. We describe a CCD camera-based imaging instrument, equipped with both a high-pressure Xenon arc lamp and a UV transilluminator, which provides broad-band wavelength coverage (380-700 nm and UV). With six-position filter wheels, both excitation and emission wavelengths may be selected, providing optimal measurement and quantitation of virtually any dye and allowing excellent spectral resolution among different fluorophores. While spatial resolution of conventional fixed CCD camera imaging systems is typically inferior to laser scanners, this problem is circumvented with the new instrument by mechanically scanning the CCD camera over the sample and collecting multiple images that are subsequently automatically reconstructed into a complete high-resolution image. By acquiring images in succession, as many as four different fluorophores may be evaluated from a gel. The imaging platform is suitable for analysis of the wide range of dyes and tags commonly encountered in proteomics investigations. The instrument is unique in its capabilities of scanning large areas at high resolution and providing accurate selectable illumination over the UV/visible spectral range, thus maximizing the efficiency of dye multiplexing protocols.

Arabidopsis Proteins↗
PubMed2003

High-content proteomics: fluorescence multiplexing using an integrated, high-sensitivity, multiwavelength charge-coupled device imaging system.

The detection of proteins in 2-D gels and their subsequent identification by MS is still the "gold standard" in proteomics. Fluorescent detection has increasingly replaced colorimetric and radiometric detection on gels and blots. The reasons for this are multiple and varied and include higher sensitivity, better quantitation, increased dynamic range, speed, safety and ease of use. Unlike other methods, fluorescent protein detection is also typically very consistent in response from protein to protein and in many cases is compatible with MS methods for protein identification. The superior sensitivity and benefits achieved by fluorescent techniques have spurred the development of instrumentation capable of delivering precise, sensitive, high-resolution image acquisition over a wide variety of excitation and emission wavelengths. This report focuses on applications using the highly sensitive, charge-coupled device based ProXPRESS multilabel imager, readily configurable for image acquisition over a wide variety of wavelengths (380-700 nm and ultraviolet (UV)) using xenon lamp or UV excitation. The ability to simultaneously detect enzyme activities or protein modifications with different color fluorescent probes in addition to total protein amounts (multiplexing) allows the further mining of proteomic data content from a single set of protein samples. To this end, the development of instrumentation that enables a multiplexing strategy will become central to in-depth proteomic studies. The ProXPRESS maximizes the efficiency of experimental strategies that require flexibility and multicolor fluorescence detection.

Electrophoresis, Gel, Two-Dimensional↗
PubMed2003

Optimized bioregenerative space diet selection with crew choice.

Previous studies on optimization of crew diets have not accounted for choice. A diet selection model with crew choice was developed. Scenario analyses were conducted to assess the feasibility and cost of certain crew preferences, such as preferences for numerous-desserts, high-salt, and high-acceptability foods. For comparison purposes, a no-choice and a random-choice scenario were considered. The model was found to be feasible in terms of food variety and overall costs. The numerous-desserts, high-acceptability, and random-choice scenarios all resulted in feasible solutions costing between 13.2 and 17.3 kg ESM/person-day. Only the high-sodium scenario yielded an infeasible solution. This occurred when the foods highest in salt content were selected for the crew-choice portion of the diet. This infeasibility can be avoided by limiting the total sodium content in the crew-choice portion of the diet. Cost savings were found by reducing food variety in scenarios where the preference bias strongly affected nutritional content.

Astronauts↗
PubMed2003

Work measurement for estimating food preparation time of a bioregenerative diet.

During space missions, such as the prospective Mars mission, crew labor time is a strictly limited resource. The diet for such a mission (based on crops grown in a bioregenerative life support system) will require astronauts to prepare their meals essentially from raw ingredients. Time spent on food processing and preparation is time lost for other purposes. Recipe design and diet planning for a space mission should therefore incorporate the time required to prepare the recipes as a critical factor. In this study, videotape analysis of an experienced chef was used to develop a database of recipe preparation time. The measurements were highly consistent among different measurement teams. Data analysis revealed a wide variation between the active times of different recipes, underscoring the need for optimization of diet planning. Potential uses of the database developed in this study are discussed and illustrated in this work.

Astronauts↗
PubMed2002

Polysaccharide analysis using carbohydrate gel electrophoresis: a method to study plant cell wall polysaccharides and polysaccharide hydrolases.

A method to characterize plant cell wall polysaccharides is presented. The complexity of the polymer structures and the large number of different charged and uncharged monosaccharides that make up plant polysaccharides have previously made analysis technically demanding and laborious. Polysaccharide analysis using carbohydrate gel electrophoresis (PACE) relies on derivatization of reducing ends of sugars and oligosaccharides with a fluorophore, followed by electrophoresis under optimized conditions in polyacrylamide gels. We show that PACE is a sensitive and simple tool for studying the monosaccharide composition of polysaccharides and of cell wall preparations. In combination with specific hydrolases, it can be used to analyze the structure of polysaccharides. Moreover, the specificity and kinetics of the plant polysaccharide hydrolases themselves can be quickly and effectively studied. PACE can detect as little as 500 fmol of monosaccharides and 100 fmol of oligosaccharides, and it is fast and quantitative.

Arabidopsis↗