Ruthenium (II) tris-bathophenanthroline disulfonate is well suitable for Tris-Glycine PAGE but not for Bis-Tris gels

Iridium tetrazolato complexes as efficient protein staining agents

Iridium tetrazolato complexes have been illustrated as one kind of efficient protein staining agent.

Gel electrophoresis-based proteomics of senescent tissues

Cellular aging is a fundamental biological process, and mass spectrometry-based proteomics has been widely used for the global identification of age-related changes in a variety of tissues. The proteomic profiling of senescent skeletal muscles has revealed a variety of alterations in proteins associated with the contractile apparatus, cell signaling, ion homeostasis, metabolism, and the cellular stress response. Here, we outline the two-dimensional gel electrophoretic separation and fluorescent labeling of the urea-soluble protein complement from aged diaphragm muscle. This chapter describes the various experimental steps involved in gel electrophoresis-based proteomics, including protein extraction, isoelectric focusing, slab gel electrophoresis, fluorescence labeling, image analysis, protein digestion, mass spectrometric identification of proteins and immunoblotting.

Malignant transformation in a defined genetic background: proteome changes displayed by 2D-PAGE

Background

Cancer arises from normal cells through the stepwise accumulation of genetic alterations. Cancer development can be studied by direct genetic manipulation within experimental models of tumorigenesis. Thereby, confusion by the genetic heterogeneity of patients can be circumvented. Moreover, identification of the critical changes that convert a pre-malignant cell into a metastatic, therapy resistant tumor cell, however, is one necessary step to develop effective and selective anti-cancer drugs. Thus, for the current study a cell culture model for malignant transformation was used: Primary human fibroblasts of the BJ strain were sequentially transduced with retroviral vectors encoding the genes for hTERT (cell line BJ-T), simian virus 40 early region (SV40 ER, cell line BJ-TE) and H-Ras V12 (cell line BJ-TER).

Results

The stepwise malignant transformation of human fibroblasts was analyzed on the protein level by differential proteome analysis. We observed 39 regulated protein spots and therein identified 67 different proteins. The strongest change of spot patterns was detected due to integration of SV40 ER. Among the proteins being significantly regulated during the malignant transformation process well known proliferating cell nuclear antigen (PCNA) as well as the chaperones mitochondrial heat shock protein 75 kDa (TRAP-1) and heat shock protein HSP90 were identified. Moreover, we find out, that TRAP-1 is already up-regulated by means of SV40 ER expression instead of H-Ras V12. Furthermore Peroxiredoxin-6 (PRDX6), Annexin A2 (p36), Plasminogen activator inhibitor 2 (PAI-2) and Keratin type II cytoskeletal 7 (CK-7) were identified to be regulated. For some protein candidates we confirmed our 2D-PAGE results by Western Blot.

Conclusion

These findings give further hints for intriguing interactions between the p16-RB pathway, the mitochondrial chaperone network and the cytoskeleton. In summary, using a cell culture model for malignant transformation analyzed with 2D-PAGE, proteome and cellular changes can be related to defined steps of tumorigenesis.

Quantitative differential proteome analysis in an animal model for human melanoma

In fish of the genus Xiphophorus, different grades of pigment cell lesions from nevi to melanoma can be gained by simple crossbreeding. With this model, one can easily access tissues of different malignancies from animals with highly identical genetic background. To find protein expression differences between healthy, benign and malignant tissues, we performed 2D PAGE and DIGE and found among regulated proteins antioxidant proteins that were overexpressed with increasing malignancy.