Preparation and analysis of plant and plastid proteomes by 2DE

Proteomic dissection of the chloroplast: Moving beyond photosynthesis

Chloroplast, the photosynthetic machinery, converts photoenergy to ATP and NADPH, which powers the production of carbohydrates from atmospheric CO₂ and H₂O. It also serves as a major production site of multivariate pro-defense molecules, and coordinate with other organelles for cell defense. Chloroplast harbors 30-50% of total cellular proteins, out of which 80% are membrane residents and are difficult to solubilize. While proteome profiling has illuminated vast areas of biological protein space, a great deal of effort must be invested to understand the proteomic landscape of the chloroplast, which plays central role in photosynthesis, energy metabolism and stress-adaptation. Therefore, characterization of chloroplast proteome would not only provide the foundation for future investigation of expression and function of chloroplast proteins, but would open up new avenues for modulation of plant productivity through synchronizing chloroplastic key components. In this review, we summarize the progress that has been made to build new understanding of the chloroplast proteome and implications of chloroplast dynamicsing generate metabolic energy and modulating stress adaptation.

Global Proteomic Profiling and Identification of Stress-Responsive Proteins Using Two-Dimensional Gel Electrophoresis

Global proteome profiling is a direct representation of the protein set in an organism, organ, tissues, or an organelle. One of the main objectives of proteomic analysis is the comparison and relative quantitation of proteins under a defined set of conditions. Two-dimensional gel electrophoresis (2-DE) has gained prominence over the last 4 decades for successfully aiding differential proteomics, providing visual confirmation of changes in protein abundance, which otherwise cannot be predicted from genome analysis. Each protein spot on 2-DE gel can be analyzed by its abundance, location, or even its presence or absence. This versatile gel-based method combines and utilizes the finest principle for separation of protein complexes by virtue of their charge and mass, visual mapping coupled with successful mass spectrometric identification of individual proteins.