RESUMO
BACKGROUND: The mitogen activated protein kinase (MAPK) pathways are known to be deregulated in many human malignancies. Phosphopeptide identification of protein-kinases and site determination are major challenges in biomedical mass spectrometry (MS). P38 and HuR protein kinases have been reported extensively in the general principles of signalling pathways modulated by phosphorylation, mainly by molecular biology and western blotting techniques. Thus, although it has been demonstrated they are phosphorylated in different stress/stimuli conditions, the phosphopeptides and specific amino acids in which the phosphate groups are located in those protein kinases have not been shown completely. METHODS: We have combined different resins: (a) IMAC (Immobilized Metal Affinity Capture), (b) TiO2 (Titanium dioxide) and (c) SIMAC (Sequential Elution from IMAC) to isolate phosphopeptides from p38 and HuR protein kinases in vitro.Different phosphopeptide MS strategies were carried out by the LTQ ion Trap mass spectrometer (Thermo): (a) Multistage activation (MSA) and (b) Neutral loss MS3 (DDNLMS3).In addition, Molecular Dynamics (MD) bioinformatic simulation has been applied in order to simulate, over a period of time, the effects of the presence of the extra phosphate group (and the associated negative charge) in the overall structure and behaviour of the protein HuR.This study is supported by the Declaration of Helsinki and subsequent ethical guidelines. RESULTS: The combination of these techniques allowed for:(1) The identification of 6 unknown phosphopeptides of these protein kinases. (2) Amino acid site assignments of the phosphate groups from each identified phosphopeptide, including manual validation by inspection of all the spectra. (3) The analyses of the phosphopeptides discovered were carried out in four triplicate experiments to avoid false positives getting high reproducibility in all the isolated phosphopeptides recovered from both protein kinases. (4) Computer simulation using MD techniques allowed us to get functional models of both structure and interactions of the previously mentioned phosphorylated kinases and the differences between their phosphorylated and un-phosphorylated forms. CONCLUSION: Many research studies are necessary to unfold the whole signalling network (human proteome), which is so important to advance in clinical research, especially in the cases of malignant diseases.
RESUMO
An encouraging approach for the diagnosis and effective therapy of immunological pathologies, which would include cancer, is the identification of proteins and phosphorylated proteins. Disease proteomics, in particular, is a potentially useful method for this purpose. A key role is played by protein phosphorylation in the regulation of normal immunology disorders and targets for several new cancer drugs and drug candidates are cancer cells and protein kinases. Protein phosphorylation is a highly dynamic process. The functioning of new drugs is of major importance as is the selection of those patients who would respond best to a specific treatment regime. In all major aspects of cellular life signalling networks are key elements which play a major role in inter- and intracellular communications. They are involved in diverse processes such as cell-cycle progression, cellular metabolism, cell-cell communication and appropriate response to the cellular environment. A whole range of networks that are involved in the regulation of cell development, differentiation, proliferation, apoptosis, and immunologic responses is contained in the latter. It is so necessary to understand and monitor kinase signalling pathways in order to understand many immunology pathologies. Enrichment of phosphorylated proteins or peptides from tissue or bodily fluid samples is required. The application of technologies such as immunoproteomic techniques, phosphoenrichments and mass spectrometry (MS) is crucial for the identification and quantification of protein phosphorylation sites in order to advance in clinical research. Pharmacodynamic readouts of disease states and cellular drug responses in tumour samples will be provided as the field develops. We aim to detail the current and most useful techniques with research examples to isolate and carry out clinical phosphoproteomic studies which may be helpful for immunology and cancer research. Different phosphopeptide enrichment and quantitative techniques need to be combined to achieve good phosphopeptide recovery and good up- and-down phospho-regulation protein studies.
RESUMO
La Garantía de Calidad es un elemento central para el funcionamientode todo laboratorio, y va más allá de únicamente disponer de controles decalidad internos y externos en la determinación analítica. La Sociedad Espa-ñola de Inmunología (SEI) promueve un proceso para la selección de un centro responsable (CR) donde desarrollar un programa concreto para la deGarantía Externa de Calidad para Laboratorios de Inmunología Diagnósticaasociado a la Sociedad Española de Inmunología (GECLID-SEI). Este escrito presenta los aspectos principales de este proceso que debería permitir laestructuración del GECLID-SEI (AU)
Quality assurance is a key element for the functioning of any laboratory, and it goes further than just the internal and external quality controls of analytical parameters. The Spanish Society for Immunology (SEI)promotes a process to select a Center (CR) that will develop a completeprogram of External Quality Assurance for Diagnostic Immunology Laboratories, associated with the Spanish Society for Immunology (GECLIDSEI). This text presents the main aspects of this process that should allowstructuring the GECLID-SE (AU)
Assuntos
Humanos , Laboratórios/normas , Testes Imunológicos/normas , Técnicas Imunológicas/normas , Amostragem para Garantia da Qualidade de Lotes/métodos , Controle de QualidadeRESUMO
Despite their clinical utility and the importance that laboratory testshave in APS diagnosis, probably the most important drawback of suchtests is the elevated intra- and inter-laboratory variation. The aim of thepresent work was to assess the multilaboratory performance of aCL (..) (AU)
A pesar de la indudable utilidad clínica y de la importancia de laspruebas de laboratorio en el diagnóstico del síndrome antifosfolípido(APS), probablemente el mayor defecto de dichas pruebas es su elevadavariabilidad intra- e inter-laboratorio. El objetivo del presente trabajo fueevaluar el comportamiento de los ensayos (..) (AU)
