Two-dimensional Gel Electrophoresis System Research Articles

Hydrophobicity and molecular mass-based separation method for autoantibody discovery from mammalian total cellular proteins.

Serum autoantibody profiles are unique to individuals and reflect the level and history of autoimmunity and tumor immunity. The identification of autoantibody biomarkers is critical for the development of immune monitoring systems for immune-related disorders. Here, we present a practical method for large-scale autoantibody discovery using total cellular proteins from cultured mammalian cells. We found that nucleic acid-free and fully denatured water-soluble total cellular proteins from mammalian cells were superior, allowing precise separation by reversed-phase HPLC after preparing a large set of homogeneous total cellular proteins. After separating the proteins based on hydrophobicity, the fractionated samples were subjected to molecular mass analysis using conventional SDS-PAGE. The resulting two-dimensional gel electrophoresis was successfully employed for immune blotting and LC-MS/MS analysis. All procedures, including TRIzol-based total cellular protein extraction, solubilization of denatured proteins, reversed-phase HPLC separation, and SDS-PAGE, were highly reproducible and easily scalable. We propose this novel two-dimensional gel electrophoresis system as an alternative proteomics-based methodology suitable for large-scale autoantibody discovery.

Physiological and Proteomic Insights Into Red and Blue Light-Mediated Enhancement of in vitro Growth in Scrophularia kakudensis-A Potential Medicinal Plant.

The current study has determined the effect of red and blue lights on the enhancement of growth, antioxidant property, phytochemical contents, and expression of proteins in Scrophularia kakudensis. In vitro-grown shoot tip explants of S. kakudensis were cultured on the plant growth regulator-free Murashige and Skoog (MS) medium and cultured under the conventional cool white fluorescent lamp (control), blue light-emitting diodes (LED) light, or red LED light. After 4 weeks, growth, stomatal ultrastructure, total phenols and flavonoids, activities of antioxidant enzymes, and protein expressions were determined. Interestingly, blue or red LED treatment increased the shoot length, shoot diameter, root length, and biomass on comparison with the control. In addition, the LED treatments enhanced the contents of phytochemicals in the extracts. The red LED treatment significantly elicited the accumulation of flavonoids in comparison with the control. In accordance with the secondary metabolites, the LED treatments modulated the activities of antioxidant enzymes. Moreover, the proteomic insights using two-dimensional gel electrophoresis system revealed the proteins involved in transcription and translation, carbohydrate mechanism, post-translational modification, and stress responses. Taken together, the incorporation of blue or red LED during in vitro propagation of S. kakudensis can be a beneficial way to increase the plant quality and medicinal values of S. kakudensis.

Evaluation of proteome profiles of Salix spp. pollen and relationship between glucose oxidase activity and pollen content in willow honey

Proteins from hand- and bee- collected pollen were isolated and separated in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional gel electrophoresis (2DE) system as well by direct gel-free mass spectrometry (MS) analysis. Total thirty six plant proteins with known functions and three uncharacterized were identified using mass spectrometry (MS) techniques from fourteen protein spots separated in 2D gel electrophoresis. Our study revealed two forms of profilin proteins with their slight different mass 14.19 kDa and 14.09 kDa and beta actin fragment was 33.25 kDa both in hand and bee collected pollen as well proteins of thioredoxin family with molecular weight - 47.29 kDa. The antioxidant enzyme glucose oxidase (GOX) activity was investigated in twelve samples of monofloral willow honey, having Salix spp. pollen from 44.7 % to 80.2 %. Data of paired regression analysis between Salix spp. pollen content and GOX activity show moderate and negative correlation coefficient (r= - 0.56).
 Keywords: willow pollen; honey; protein expression; separation; two-dimensional electrophoresis; mass spectrometry

Identification of genes involved in rice seed priming in the early imbibition stage.

Phase II of seed imbibition is a critical process during seed priming. To identify genes involved in rice seed priming, the altered proteins between the dry and imbibed (24h) seeds were compared using a two-dimensional gel electrophoresis system in this study. Ten significantly changed proteins (fold change≥twofold; P<0.01) were successfully identified, which could be categorised as carbohydrate and protein biosynthesis and metabolism-related, signalling-related, storage and stress-related proteins. A meta-analysis indicated that the highest expression of the identified genes was at the milk and dough stages and in the endosperm tissue. Quantitative real-time PCR analysis showed that there was significant variation in gene expression (except FAD-dependent oxidoreductase) in embryos during seed priming (0-48h). The expression of genes associated with stress appeared at the early imbibition stage, while those associated with carbohydrate metabolism, protein synthesis and signalling increased at the late imbibition stage. Three identified proteins (glucose-1-phosphate adenylyltransferase large subunit, aminotransferase and prolamin precursor) had similar transcript and protein expression patterns in embryos. Based on phenotype and gene expression, the optimal stop time for seed priming is 24h, when these three genes have relatively low expression, followed by significant induction during imbibition in embryos. These three genes are ideal candidate biomarkers for rice seed priming.

Antioxidant effects of carnitine supplementation on 14-3-3 protein isoforms in the aged rat hippocampus detected using fully automated two-dimensional chip gel electrophoresis

We here described the antioxidant effects of carnitine supplementation on 14-3-3 protein isoforms in the aged rat hippocampus detected using the fully automated two-dimensional chip gel electrophoresis system (Auto2D). This system was easy and convenient to use, and the resolution obtained was more sensitive and higher than that of conventional two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). We separated and identified five isoforms of the 14-3-3 protein (beta/alpha, gamma, epsilon, zeta/delta, and eta) using the Auto2D system. We then examined the antioxidant effects of carnitine supplementation on the protein profiles of the cytosolic fraction in the aged rat hippocampus, demonstrating that carnitine supplementation suppressed the oxidation of methionine residues in these isoforms. Since methionine residues are easily oxidized to methionine sulfoxide, the convenient and high-resolution 2-D PAGE system can be available to analyze methionine oxidation avoiding artifactual oxidation. We showed here that the Auto2D system was a very useful tool for studying antioxidant effects through proteomic analysis of protein oxidation.

Quantitative proteomics analysis highlights the role of redox hemostasis and energy metabolism in human embryonic stem cell differentiation to neural cells

Neural differentiation of human embryonic stem cells (hESCs) is a unique opportunity for in vitro analyses of neurogenesis in humans. Extrinsic cues through neural plate formation are well described in the hESCs although intracellular mechanisms underlying neural development are largely unknown. Proteome analysis of hESC differentiation to neural cells will help to further define molecular mechanisms involved in neurogenesis in humans. Using a two-dimensional differential gel electrophoresis (2D-DIGE) system, we analyzed the proteome of hESC differentiation to neurons at three stages, early neural differentiation, neural ectoderm and mature neurons. Out of 137 differentially accumulated protein spots, 118 spots were identified using MALDI-TOF/TOF and LC MS/MS. We observed that proteins involved in redox hemostasis, vitamin and energy metabolism and ubiquitin dependent proteolysis were more abundant in differentiated cells, whereas the abundance of proteins associated with RNA processing and protein folding was higher in hESCs. Higher abundance of proteins involved in maintaining cellular redox state suggests the importance of redox hemostasis in neural differentiation. Furthermore, our results support the concept of a coupling mechanism between neuronal activity and glucose utilization. The protein network analysis showed that the majority of the interacting proteins were associated with the cell cycle and cellular proliferation. These results enhanced our understanding of the molecular dynamics that underlie neural commitment and differentiation. In highlighting the role of redox and unique metabolic properties of neuronal cells, the present findings add insight to our understanding of hESC differentiation to neurons. The abundance of fourteen proteins involved in maintaining cellular redox state, including 10 members of peroxiredoxin (Prdx) family, mainly increased during differentiation, thus highlighting a link of neural differentiation to redox. Our results revealed markedly higher expression of genes encoding enzymes involved in the glycolysis and amino acid synthesis during differentiation. Protein network analysis predicted a number of critical mediators in hESC differentiation. These proteins included TP53, CTNNB1, SMARCA4, TNF, TERT, E2F1, MYC, RB1, and AR.

Identification of canine platelet proteins separated by differential detergent fractionation for nonelectrophoretic proteomics analyzed by Gene Ontology and pathways analysis.

During platelet development, proteins necessary for the many functional roles of the platelet are stored within cytoplasmic granules. Platelets have also been shown to take up and store many plasma proteins into granules. This makes the platelet a potential novel source of biomarkers for many disease states. Approaches to sample preparation for proteomic studies for biomarkers search vary. Compared with traditional two-dimensional polyacrylamide gel electrophoresis systems, nonelectrophoretic proteomics methods that employ offline protein fractionation methods such as the differential detergent fractionation method have clear advantages. Here we report a proteomic survey of the canine platelet proteome using differential detergent fractionation coupled with mass spectrometry and functional modeling of the canine platelet proteins identified. A total of 5,974 unique proteins were identified from platelets, of which only 298 (5%) had previous experimental evidence of in vivo expression. The use of offline prefractionation of canine proteins by differential detergent fractionation resulted in greater proteome coverage as compared with previous reports. This initial study contributes to a broader understanding of canine platelet biology and aids functional research, identification of potential treatment targets and biomarkers, and sets a new standard for the resting platelet proteome.

Proteomic analysis of ‘Zaosu’ pear (Pyrus bretschneideri Rehd.) and its red skin bud mutation

BackgroundBreeding for strong red skin color is an important objective of the pear breeding program. There are few reports of proteome research in green skin pear and its red skin bud mutation. The manuscript at hand is one of the first studies dealing with 2D-PAGE-based analysis of pear fruits and leaves, establishing a suitable sample preparation and testing different 2D-PAGE protocols. Therefore, it may grant a basis for further studies on the pear proteome being the studies main goal. A proteomic analysis was conducted on leaves and fruits of ‘Zaosu’ pear (Pyrus bretschneideri Rehd.) and its red skin bud mutation in order to reveal their genetic differences in the protein level.ResultsIn the present study, the optimized two-dimensional (2-D) gel electrophoresis system of pear leaf and fruit was set up, and applied to analyze the leaves and fruit protein. The interesting peptide fragments were determined using 4800 Plus MALDI TOF/TOFTM Analyzer mass spectrometer, and the sequence obtained was blasted in NCBInr to identify the differentially-expressed protein. In the 1.5-fold differently-expressed proteins between ‘Zaosu’ pear and its mutant, 10 out of 35 proteins in fruit and 12 out of 24 ones in leaves were identified successfully. Among the 22 identified proteins, 7 protein spots were related to photosynthesis and energy metabolism; 4 were associated with environmental stress; 4 with disease defense; 2 with amino acid metabolism; 2 with cytoskeleton; 1 with antioxidant function; 1 with calcium metabolism; and 1 with unknown function. Moreover, related physiological index, such as chlorophyll content, Rubisco content and polyphone oxidase activity, were different between ‘Zaosu’ pear and its mutant.ConclusionA 2-D gel electrophoresis system of pear leaves and fruits was established, which was suitable for the analysis of proteome comparison. To the best of our knowledge, we have performed the first analysis of the proteomic changes in leaves and fruits of ‘Zaosu’ pear and its red skin bud mutation. Our study provides important information on the use of proteomic methods for studying protein regulation of ‘Zaosu’ pear and its red skin bud mutation.

Proteome analysis of proteins related to aggressive periodontitis combined with neutrophil chemotaxis dysfunction

Some patients suffering from aggressive periodontitis (Ag-P) also display neutrophil chemotaxis dysfunction. In this study, we attempted to identify the proteins involved in Ag-P associated with neutrophil chemotaxis dysfunction using proteome analysis. A two-dimensional fluorescence difference gel electrophoresis system was used to detect differences in protein expression between neutrophils from four patients suffering from Ag-P combined with neutrophil chemotaxis dysfunction and those from four controls. Moreover, the mRNA levels of the proteins identified by the above method were examined in neutrophils from four types of subjects using the real-time polymerase chain reaction: twenty patients suffering from Ag-P with or without the dysfunction, 15 patients with chronic periodontitis, and 15 controls. Four proteins, lactoferrin, caldesmon, heat shock protein 70, and stac, displayed a higher protein expression level in the neutrophils from the patients suffering from Ag-P combined with the neutrophil dysfunction than in those from the control group. The caldesmon mRNA levels in the neutrophils from the patients suffering from Ag-P combined with the neutrophil dysfunction were high compared with those in the neutrophils from the patients suffering from the other two types of periodontitis and those from the control group. Caldesmon may be a marker of Ag-P combined with neutrophil chemotaxis dysfunction.

Construction of Two-Dimensional Polyacrylamide Gel Electrophoresis System for Proteins in Brassica napus

Abstract The purpose of this study was to establish a suitable 2-dimensional polyacrylamide gel electrophoresis (2-DE) system for proteomics analysis in Brassica napus. Proteins of rapeseed variety 08127 were separated in gel brands (pH 4–7) using trichloroacetic extraction method under the improved isoelectric focusing (IEF) procedure. A clean 2-DE map was obtained, indicating that the system was effective and suitable for B. napus. This system was validated using young seedling, leaves, and stems from other varieties, and the results were similar to that of variety 08127. The proteomics profiling of seedlings in different ages of B. napus was then analyzed on the basis of this system. In the stems of 30-day-age seedlings, 20 up-regulated and 51 down-regulated proteins were found with differential expression more than 2 folds compared to their corresponding proteins in 15-day-age stems. A few differential protein spots were identified using mass spectrometry method, indicating the effectiveness of the 2-DE polyacrylamide gel electrophoresis system established in this study.

The 30th anniversary of quasispecies

The meeting on ‘Quasispecies: past, present and future’ took place between 17 and 18 November 2008, in Barcelona, Spain, and was organized by J. Gomez, C. Lopez‐Galindez, M.A. Martinez & A. Mas. ![][1] A meeting was held in Barcelona, Spain, in November 2008 to celebrate the 30th anniversary of the publication of the article that described the extensive genetic heterogeneity of bacteriophage Qβ (Domingo et al , 1978), which is considered to mark the beginning of experimental studies on viral quasispecies. This meeting was held at the impressive fifteenth century building of the ancient Hospital de la Santa Creu in the old town of Barcelona, which is now the headquarters of the Institut d'Estudis Catalans, and was attended by C. Weissmann (Jupiter, FL, USA), M. Billeter (Zurich, Switzerland) and E. Domingo (Madrid, Spain), who were three early protagonists of the phage Qβ work at the University of Zurich in the 1970s. Several speakers presented their results on the theoretical aspects of the population dynamics of cells and viruses, the clinical implications of quasispecies, and extensions of the quasispecies concept to cellular genes and prions. The meeting was introduced by A. Mas (Albacete, Spain), who reflected on the increasing impact that quasispecies have had in the scientific literature over the past three decades, and quoted some of the key references on viral quasispecies (Martell et al , 1992; Meyerhans et al , 1989; Najera et al , 1995; Vignuzzi et al , 2006; for a historical review of the impact of quasispecies in virology, see Holland, 2006). The scientific presentations were opened by Weissmann and Domingo, who were the last and first authors of the 1978 paper, respectively. Their talks conveyed the scientific atmosphere of the 1970s—when molecular biology was carried out with few recombinant‐DNA techniques—to a young audience. Nucleic‐acid sequencing was in … [1]: /embed/graphic-1.gif

Miniaturized two-dimensional gel electrophoresis of high-molecular-weight proteins using low-concentration multifilament-supporting gel for isoelectric focusing

A miniaturized two-dimensional gel electrophoresis (2-DE) system was constructed with a multifilament-supporting (MFS) gel as a first-dimensional gel for isoelectric focusing (IEF). The MFS gel was 1 mm in diameter, had a multifilament yarn of acrylic as a gel-support, and could provide low-concentration (2.5%T) polyacrylamide with sufficient mechanical strength, resulting in fast IEF, and clear 2-D spots due to the relatively large pore and improved transfer efficiency from the first-dimensional gel to the second-dimensional one of especially high-molecular-weight (HMW) proteins. In this study, by using the MFS gel of 4 cm in length as a miniaturized IEF gel, three colored proteins were separated in 8 min, which was about twice faster than using the MFS gel of standard length (7 cm). The second-dimensional gel was also miniaturized to be 55 mm wide, 40 mm long and 0.75 mm thick. The low-concentration MFS gel after IEF was easily transferred onto the top of the miniaturized second-dimensional gel with a tweezers. By using the miniaturized 2-DE system, the HMW size marker was separated in 30 min by IEF and in 25 min by native-polyacrylamide gel electrophoresis (Native-PAGE), which was at least twice faster than by using the standard size 2-DE system using MFS gel. This miniaturized 2-DE system could be expected as a useful separation method for fast protein diagnosis and screening.

Differential analysis of protein profiles of gallbladder bile from patients with cholesterol cholelithiasis and controls

Objective To elucidate the mechanism of formation of cholesterol cholelithiasis, thisstudy is designed to establish two-dimensional polyacrylamide gel electrophoresis system for differenti-al analysis of the proteome of gallbladder bile from cholesterol cholelithiasis patients and control ones.Methods Total proteins of gallbladder bile were extracted from the subjects in two groups and the protein profiles were established by using the immobilized pH gradient two-dimensional electrophoresis respectively. These maps were analyzed by ImageMaster two-dimensional eleetrophoresis analysis software. Results The concentrations of bile proteins from cholesterol cholelithiasis patients and con-trol ones were (6.4824±0.3403)mg/ml and (2.3156±0.3064)mg/ml(P<0.01), respectively. The average matched protein spots were 465±71 and 407±85 in the two groups, respectively. The matched rates were 71.70% and 68.38% correspondingly. There were 269 matched spots in the two reference gels maps and the matched rate was 61.70%. A total of 34 differential protein spots were i-dentified, 16 expressed highly in cholesterol cholelithiasis patients but lowly in the control ones, while 18 expressed just in the opposite way. Conclusion The differential protein profiles of gallbladder bile between cholesterol cholelithiasis patients and controls have been established and several differential protein spots are found. The data may be a basis for further screening the key regulators of formation of cholesterol eholelithiasis. Key words: Cholelithiasis; Two-dimensional gel electrophoresis; Proteome; Bile

Two‐dimensional differential gel electrophoresis/analysis of diethylnitrosamine induced rat hepatocellular carcinoma

Diethylnitrosamine (DEN) is a known carcinogen that can alkylate DNA molecules. In rats, DEN-induced hepatocellular carcinoma (HCC) model is well established. In this study, we used a two-dimensional differential gel electrophoresis (2D-DIGE) system and liquid chromatography/mass spectrometry/mass spectrometry to identify the differential expression protein profiles between the DEN-induced HCC and healthy liver cells. Western blotting and semiquantitative RT-PCR were used to further confirm the results. Seventeen differentially expressed spots were identified in DEN-induced HCC cells. Among all, the most prominent upregulated proteins include the members of the glutathione S-transferase super family, aldo-keto reductase superfamily and proteins involved in the response to oxidative stress. Downregulation was observed in 2 proteins that were known to contribute to hepatic dysfunction. This study provides the first comprehensive protein profiling of the DEN-induced HCC in rats. This model simulates the differential protein expression of human HCC and may be useful for further understanding the mechanism of HCC tumorigenesis.

Proteomic assessment of resistance to the fumigant phosphine in the lesser grain borer, Rhyzopertha dominica (F.)

A previous publication compared a strain of the stored-grain pest beetle, Rhyzopertha dominica, resistant to the fumigant phosphine, with a susceptible strain using two-dimensional polyacrylamide gel electrophoresis. Certain proteins appeared to differ and the authors proposed that arginine kinase in particular might be used as a marker for the rapid monitoring of resistance in this species and other pests of stored grain. Here an expanded set of susceptible and resistant strains is surveyed using the two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) system. Of hundreds of spots only two showed a significant difference between the resistant and susceptible strains and the magnitudes of those differences were less than three-fold. Arginine kinase spots were identified but they did not differ significantly. The proposal that certain abundant proteins of R. dominica might be used as markers of phosphine resistance was not supported by the present study.

Stability of the proteasome can be regulated allosterically through engagement of its proteolytic active sites

The 26S proteasome holoenzyme is formed by the association of a 20S core particle (CP) with a 19S regulatory particle (RP). The CP-RP interaction is labile and subject to regulation in vivo, but the factors controlling this association are poorly understood. Here we describe an in vitro proteasome reconstitution assay and a high-resolution, two-dimensional gel electrophoresis system. Using these techniques, we find that a yeast CP-RP complex can contain a substoichiometric amount of tightly bound, essentially non-exchangeable ATP. However, this nucleotide is dispensable for gating of the CP channel, provided that the CP-RP complex is preserved by the Ecm29 protein. Unexpectedly, proteasome inhibitors are potent in stabilizing proteasomes against the dissociation of CP-RP. These data indicate that active sites of the CP communicate with bound RP, despite their spatial separation. We propose that ongoing protein degradation may suppress proteasome disassembly, thereby enhancing the processivity of proteolysis.

A reference map of human nasopharyngeal squamous carcinoma proteome

In order to conduct a comparative proteomics study of human nasopharyngeal carcinoma (NPC) to understand the molecular mechanisms that participate in the formation of NPC, the two-dimensional gel electrophoresis (2-DE) reference map of human NPC tissue proteome was described. To provide a high level of reproducibility between gels and accurately array each protein expressed in NPC tissue proteome, the two-dimensional polyacrylamide gel electrophoresis system, modified colloidal Coomassie Brilliant Blue staining method and ImageMaster 2D Platinum image analysis software were used. The NPC 2-DE maps show that high quality and good reproducibility of the 2-DE gel pattern was attained. An average total of 1,100 protein spots were separated by 2-DE, visualized by a modified colloidal Coomassie Brilliant Blue staining method. A synthesized 2-DE reference gel was acquired after detailed analysis of the NPC 2-DE gel maps, and 216 medium to high abundant spots were identified as landmark spots of NPC 2-DE gel, which expressed on >75% of gels. To provide an unambiguous identification of the landmark spots in gels, MALDI-TOF, ESI-Q-TOF mass spectrometry and database search were used to identify the proteins expressed in NPC tissue proteome. Between the 216 landmark spots, all proteins were identified with MALDI-TOF at first, 41 of which were identified with both MALDI-TOF and ESI-Q-TOF. All identified proteins were classified in terms of their subcellular localization and physiological function with information from SWISS-PROT and NCBI websites. According to our knowledge this is the first 2-DE reference map of human NPC. This reference map will serve as a basis for further studies of human NPC and the reference map data will be used to expand the proteome database of human NPC, which can be accessed in our website (http://www.xyproteomics.org/).

Analysis of Two-Dimensional Gel Electrophoresis Images of Protein from Posterior Silk Gland of Silkworm ( Bombyx mori) on Day 1 and Day 4 in the 5th Instar Stage

The posterior silk gland (PSG) of silkworm is an important organ where fibroin is synthesized and secreted exclusively. Because fibroin constitutes 75–80% of the silk filament, the mechanism governing fibroin secretion, quality and yield of cocoon can be elucidated by the study on the PSG. Using two-dimensional gel electrophoresis (2–DE) and image analysis system, the changes in the protein composition in the PSG cell were investigated on the day 1 (D1) and day 4 (D4) in the 5th instar stage from five different strains of silkworm ( Bombyx mori). While differences at protein level between days and strains were far less than those observed at the gene level using EST analysis. The change trends in protein composition from D1 to D4 were diverse among the different strains. The results suggest that the secretion of fibroin is regulated by multiple proteins. The site of regulation and the proteins responsible for the regulation vary with the strain, which leads to differences between strains in the capacity of fibroin secretion in the PSG cell.

Proteomic Analysis of the Trabecular Meshwork of Rats in a Steroid-Induced Ocular Hypertension Model: Downregulation of Type I Collagen C-Propeptides

Purpose: To investigate global protein expression profiles in the trabecular meshwork (TM) of normal and glucocorticoid-induced ocular hypertensive rat eyes by proteomic analysis, which has not yet been conducted to date. Materials and Methods: A rat ocular hypertension model was produced by topical application of dexamethasone (DEX) for 4 weeks. Age-matched untreated rats served as controls. Intraocular pressure (IOP) was monitored by an electronic tonometer. TM protein expression profiling and protein identification was carried out by a two-dimensional fluorescence differential gel electrophoresis (2-D DIGE) system and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, respectively. Results: In DEX-treated rats, average IOP was elevated significantly, as compared with controls. By the DEX treatment, 14 TM protein spots were up- or downregulated consistently in 2-D DIGE analyses. Proteins exhibiting more than 2-fold statistically significant change were identified by MALDI-TOF mass spectrometry. αA-Crystallin and βA₃-crystallin were upregulated, while the C-propeptides of type I collagen were downregulated. Conclusion: Relatively short-term glucocorticoid application induced alteration in the expression of a number of proteins, including downregulation of type I collagen C-propeptides. This could reflect impaired collagen turnover in the TM of glucocorticoid-treated eyes.

An Integrated Proteomic Workflow for Two-Dimensional Differential Gel Electrophoresis and Robotic Spot Picking

New technologies have advanced the field of proteomics, and a number of companies have developed innovative platforms to drive this research. However, significant challenges are often encountered when trying to integrate complementary technologies from multiple manufacturers. We have developed a software and hardware solution to integrate the Ettan two-dimensional difference gel electrophoresis (2-D DIGE) system (GE Healthcare) with the Investigator ProPic spot picking robot (Genomic Solutions). We have analyzed protein sample preparations from bacterial and mammalian sources to demonstrate a new workflow with increased throughput for gel-based proteomics.