Review A practical guide to nano-LC troubleshootingCapillary LC is one of the most powerful analytical tools available for separation scientists. Its unique analytical properties are associated with numerous technical issues that may cause operation of such systems to be somehow troublesome. Because of that, a good experience in capillary LC troubleshooting is required to keep the system in shape and, in effect, to obtain reliable results. In this paper, we summarize the most important issues of the capillary systems, including void and dead volumes, leakages, sample injection, and a multidimensional LC approach. The aim of this paper was to provide practical advise on system diagnosis, and to present solutions to problems discussed. Also, several exemplary nano-LC separations are included to demonstrate some typical problems encountered in our daily work.

Background: Lysine acetylation is a major post-translational modification of proteins. Results: Human glycine N-acyltransferase-like 2 is regulated by acetylation/deacetylation of lysine 19. Conclusion: Reversible lysine acetylation is important in regulating the activity and function of human glycine N-acyltransferases. Significance: Our study links post-translational modification of proteins with the production of lipid signaling molecules, the N-acyl glycines.

Phosphoglycerate mutase (PGAM), a conserved, glycolytic enzyme has been found in nucleoli of cancer cells. Here, we present evidence that accumulation of PGAM in the nucleolus is a universal phenomenon concerning not only neoplastically transformed but also non-malignant cells. Nucleolar localization of the enzyme is dependent on the presence of the PGAM2 (muscle) subunit and is regulated by insulin/IGF-1–PI3K signaling pathway as well as drugs influencing ribosomal biogenesis. We document that PGAM interacts with several 40S and 60S ribosomal proteins and that silencing of PGAM2 expression results in disturbance of nucleolar structure, inhibition of RNA synthesis and decrease of the mitotic index of squamous cell carcinoma cells. We conclude that presence of PGAM in the nucleolus is a prerequisite for synthesis and initial assembly of new pre-ribosome subunits.

The data show that the stable isotope standards and capture by anti-peptide antibodies-2D-LC-MS/MS assay can be used as an alternative method for measurement of monoclonal antibodies in clinical samples.

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