Question

8. PROTEOMICS HIGH THROUGHPUT 4-6dort 6-10 A. How Protein Expression Arrays Can Be Used To Identify Differentially Expressed Proteins In Newly Launched Transgenic Maize Species Compared To Wild Type B. Advantages of using protein arrays over DIGE C. Advantages of DIGE over 2D-PAGE D. Protocol to use Differential Gel Electrophoresis to identify a differentiall expressed protein in a newly launched transgenic cassava compared to wild type E. Disadvantages of using protein arrays F. Advantage and disadvantages of using MS MALDI TOF in protein analysis

Answer 1

a) By comparing the signals (obtained from the lysates of cells from transgenic line and wild type) when specific aptamers (that should be recognized by proteins of the transgenic line) bound to the antibody that’s attached to the solid surface.

b) Doesn’t require much time for analysis, also, isn’t as labor-intensive as DIGE and can be used to analyze proteins that are in low abundance per se in the cell.

c) It can overcome the limitations related to inter-gel variations, since this can have a considerable effect even with identical samples. Also, since the proteins of different sample types are run on the same gel they can be directly compared (since they were exposed to the same conditions), also, is less time consuming.

d) Cell lysates from the wild type and the transgenic line are mixed with the fluorescent dyes and loaded into an isoelectric focusing chromatography for first dimension and then this strip is transferred to a SDS-PAGE. After the gel is scanned with the excitation wavelength of each dye we can quantify the amount of fluorescence emitted that is directly related to the amount of protein bound to the dye.