Protein expression pattern

Figure 3.1. Protein expression mapping using 2-D electrophoresis and mass spectrometry. The purpose is to compare protein expression patterns between cell types or in the same cell type under different growth conditions. Proteins are extracted from the different cell types and separated by 2D gel electrophoresis. Image analysis programs are used to compare the spot intensities between gels and identify proteins that are differentially expressed. The protein of interest is excised from the gel and its identity is determined by mass spectrometry. The power of the method increases greatly if the identity of a large number of proteins on the gel is known and present in a database because information can then be obtained without further mass spectrometry.

Magliery, T. J. and Regan, L. (2006). Reassembled GFP Detecting protein-protein interactions and protein expression patterns. Methods Biochem. Anal. 47, 391-405. 

TABLE 8-1 Major microtubule cytoskeletal proteins of the nervous system Protein Expression pattern and distribution... 

Although efforts are underway to identify markers in serum and prostate tissue, the question arose as to whether metastatic prostate cancer cell lines accurately represent in vivo disease. It was found that in vitro cell cultures (LnCaP and PC3) shared less than 20% of proteins when compared to in vivo LCM procured malignant prostate cancer. 2D-PAGE protein profiles were used to compare normal and malignant cells to immortalized cells from the same patient. Protein expression patterns were dramatically altered when cells were grown in culture and immortalized most notably, a loss of prostate specific antigen expression was observed [18]. Thus, caution must be used when working with immortalized cell lines to discover potential disease markers. 

Dinnes DL, Marcal H, Mahler SM, Santerre JP, Labow RS. Material surfaces affect the protein expression patterns of human macrophages a proteomics approach. Journal of Biomedical Materials Research A 2007, 80, 895-908. 

Genomic biology takes a holistic approach to molecular biology and volution by studying the complete genome, its genes, and its protein expression patterns. 

A potential mechanism of action by which potential probiotic strains may impede pathogens is through the modulation of gene and/or protein expression patterns through bacterial signaling mechanisms. Interestingly, cell-free supernatants of L. acidophilus have been shown to inhibit... 

After xenobiotic/toxin exposure, differentially expressed proteins are identified by the comparison of SELDI spectra from control and treated samples. By combining groupwise statistics with N-fold regulations, single biomarkers (m/z) can be selected. As to be expected from the complexity of the proteome, in many cases no single marker will be able to discriminate between the groups. Rather, a complex pattern of multiple markers will be acquired (Figure 8). Discovery of such markers/pattems can be successful by application of multivariate statistics methods on the data set. However, for the identification of specific protein expression patterns bioinformatics tools are... 

In order to study the changes in protein expression in consequence of TCil Pl activation by the TGF-pi receptors, we used human fetal fibroblasts. In this initial study, protein expression patterns were compared between cells in a resting state in comparison to activated cells. The proteins were separated by 2-D PAGE and the protein patterns were analyzed by image analysis using the PDQUEST software (Bio-Rad). A representative expression profile of the human fibroblast proteome is shown in Figure 3, with corresponding protein spots at an expression density of approximately 1700 spots. 

Mehra, A., Lee, K. H., Hatzimanikatis, V. (2003). Insights into the relation between mRNA and protein expression patterns I. Theoretical considerations. Biotechnol. Bioeng. 84, 822-833. 

Anderson pioneered this approach by investigating the effects of Aroclor [15], methapyrilene [16] and peroxisome proliferators [17] on mouse liver proteins using 2-DE and therefore by comparing globally the changes in protein expression patterns. 

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