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Human C-C motif ligand 16 (CCL16) is a chemokine that is distinguished by a large cleavable C-terminal extension of unknown significance. Conflicting data have been reported concerning its tissue distribution and modulation of expression, rendering the biological function of CCL16 enigmatic. Here, we report an integrated approach to the characterisation of this chemokine, including a re-assessment of its expression characteristics as well as a biophysical investigation with respect to its structure and dynamics. Our data indicate that CCL16 is chiefly synthesised by hepatocytes, without an appreciable response to mediators of inflammation, and circulates in the blood as a full-length protein. While the crystal structure of CCL16 confirms the presence of a canonical chemokine domain, molecular dynamics simulations support the view that the C-terminal extension impairs the accessibility of the glycosaminoglycan binding sites and may thus serve as an intrinsic modulator of biological activity. [ABSTRACT FROM AUTHOR]

In this study, we developed and validated a CE-TOF-MS method for the quantification of glyphosate (N-(phosphonomethyl)glycine) and its major degradation product aminomethylphosphonic acid (AMPA) in different samples including beer, media from toxicological analysis with Daphnia magna, and sorption experiments. Using a background electrolyte (BGE) of very low pH, where glyphosate is still negatively charged but many matrix components become neutral or protonated, a very high separation selectivity was reached. The presence of inorganic salts in the sample was advantageous with regard to preconcentration via transient isotachophoresis. The advantages of our new method are the following: no derivatization is needed, high separation selectivity and thus matrix tolerance, speed of analysis, limits of detection suitable for many applications in food and environmental science, negligible disturbance by metal chelation. LODs for glyphosate were < 5 μg/L for both aqueous and beer samples, the linear range in aqueous samples was 5–3000 μg/L, for beer samples 10–3000 μg/L. For AMPA, LODs were 3.3 and 30.6 μg/L, and the linear range 10–3000 μg/L and 50–3000 μg/L, for aqueous and beer samples, respectively. Recoveries in beer samples for glyphosate were 94.3–110.7% and for AMPA 80.2–100.4%. We analyzed 12 German and 2 Danish beer samples. Quantification of glyphosate and AMPA was possible using isotopically labeled standards without enrichment, purification, or dilution, only degassing and filtration were required for sample preparation. Finally, we demonstrate the applicability of the method for other strong acids, relevant in food and environmental sciences such as N-acetyl glyphosate, N-acetyl AMPA (present in some glyphosate resistant crop), trifluoroacetic acid, 2-methyl-4-chlorophenoxyacetic acid, glufosinate and its degradation product 3-(methylphosphinico)propionic acid, oxamic acid, and others. [ABSTRACT FROM AUTHOR]

n impressive complexity is associated with glycoproteins due to the microheterogeneity of glycosylation as posttranslational modification giving rise to a vast number of isoforms. The full characterization of glycoproteins is difficult to achieve, and a number of analytical methods have to be combined for a detailed understanding of glycosylation. In this review, we focus on capillary electromigrative separation techniques in the formats capillary electrophoresis, micellar electrokinetic chromatography, and capillary sieving electrophoresis. These separation techniques can be applied to all levels of glycosylation analysis including intact glycoproteins, glycopeptides, and released glycans. We here discuss the separation characteristics for each method and the information that they can provide for each level. Detection issues, especially laser-induced fluorescence detection and mass spectrometry are taken into account. In addition, tables provide an overview on the achievements made from the very beginning of glycosylation research by electromigrative separation techniques. From the literature presented here it is clear, that glycosylation analysis by electromigrative separation techniques is on the edge of transition of basic research and method development towards applications. First proof-of-principle studies for in-depth glycoprotein characterization and clinical diagnosis are described. However, this overview also shows that many basic aspects of separation have not yet been fully understood and more research is necessary to be able to fully use the capabilities of electromigrative separation techniques. [ABSTRACT FROM AUTHOR]