Using Polysialylated Streptavidin as an Analytical Tool to Visualize Interaction Partners of Polysialic Acid.

The interplay of the carbohydrate polysialic acid (polySia) with its interaction partners plays an important role in several physiological systems of vertebrates. The objective of this study was to develop a flexible analytical system for visualizing interaction partners of polySia using blotting and fluorescence cell staining strategies. We selected a streptavidin-biotin system due to the wide range of commercially available tools for this analytical application. After chemical polysialylation of streptavidin, the resulting bioconjugate was used to target polySia interaction partners after they had been separated via native agarose gel electrophoresis and transferred to a PVDF membrane. Furthermore, neutrophil extracellular traps (NETs) were employed to visualize polySia interaction partners within a cellular system using fluorescence-labeled biotin. The obtained results demonstrate that polysialylated streptavidin is a flexible bioconjugate that can be applied to investigate polySia interaction partners using various blotting and fluorescence imaging techniques.