Die Plant Science Student Conference (PSSC) wird seit 20 Jahren im jährlichen Wechsel von Studierenden der beiden Leibniz-Institute IPK und IPB organisiert. Im Interview erläutern Christina Wäsch (IPK) und Carolin Apel (IPB),…
Über 600 Gäste kamen am 4. Juli ans IPB zur Langen Nacht, die Wissen schafft, um bei unserem Wissenschafts-Quiz-Parcours viel Neues zu erfahren und ihre Kenntnisse unter Beweis zu stellen. Unser Programm in diesem Jahr…
Lennicke, C.; Rahn, J.; Heimer, N.; Lichtenfels, R.; Wessjohann, L. A.; Seliger, B.;Redox proteomics: Methods for the identification and enrichment of redox-modified proteins and their applicationsProteomics16197-213(2016)DOI: 10.1002/pmic.201500268
PTMs are defined as covalent additions to functional groups of amino acid residues in proteins like phosphorylation, glycosylation, S‐nitrosylation, acetylation, methylation, lipidation, SUMOylation as well as oxidation. Oxidation of proteins has been characterized as a double‐edged sword. While oxidative modifications, in particular of cysteine residues, are widely involved in the regulation of cellular homeostasis, oxidative stress resulting in the oxidation of biomolecules along with the disruption of their biological functions can be associated with the development of diseases, such as cancer, diabetes, and neurodegenerative diseases, respectively. This is also the case for advanced glycation end products, which result from chemical reactions of keto compounds such as oxidized sugars with proteins. The role of oxidative modifications under physiological and pathophysiological conditions remains largely unknown. Recently, novel technologies have been established that allow the enrichment, identification, and characterization of specific oxidative PTMs (oxPTMs). This is essential to develop strategies to prevent and treat diseases that are associated with oxidative stress. Therefore this review will focus on (i) the methods and technologies, which are currently applied for the detection, identification, and quantification of oxPTMs including the design of high throughput approaches and (ii) the analyses of oxPTMs related to physiological and pathological conditions.
Publikation
Mattow, J.; Schmidt, F.; Höhenwarter, W.; Siejak, F.; Schaible, U. E.; Kaufmann, S. H.;Protein identification and tracking in two-dimensional electrophoretic gels by minimal protein identifiersProteomics42927-2941(2004)DOI: 10.1002/pmic.200400908
Protein identification by matrix‐assisted laser desorption/ionization mass‐spectrometry peptide mass fingerprinting (MALDI‐MS PMF) represents a cornerstone of proteomics. However, it often fails to identify low‐molecular‐mass proteins, protein fragments, and protein mixtures reliably. To overcome these limitations, PMF can be complemented by tandem mass spectrometry and other search strategies for unambiguous protein identification. The present study explores the advantages of using a MALDI‐MS‐based approach, designated minimal protein identifier (MPI) approach, for protein identification. This is illustrated for culture supernatant (CSN) proteins of Mycobacterium tuberculosis H37Rv after separation by two‐dimensional gel electrophoresis (2‐DE). The MPI approach takes into consideration that proteins yield characteristic peptides upon proteolytic cleavage. In this study, peptide mixtures derived from tryptic protein cleavage were analyzed by MALDI‐MS and the resulting spectra were compared with template spectra of previously identified counterparts. The MPI approach allowed protein identification by few protein‐specific signature peptide masses and revealed truncated variants of mycobacterial elongation factor EF‐Tu, previously not identified by PMF. Furthermore, the MPI approach can be employed to track proteins in 2‐DE gels, as demonstrated for the 14 kDa antigen, the 10 kDa chaperone, and the conserved hypothetical protein Rv0569 of M. tuberculosis H37Rv. Furthermore, it is shown that the power of the MPI approach strongly depends on distinct factors, most notably on the complexity of the proteome analyzed and accuracy of the mass spectrometer used for peptide mass determination.