Imaging and Quantification of Secreted Peroxynitrite at the Cell Surface by a Streptavidin-Biotin-Controlled Binding Probe.

The ability to detect and image secreted peroxynitrite (ONOO ) along the extracellular surface of a single cell is biologically significant, as ONOO generally exerts its function for host defense and signal transductions at the plasma membrane. However, as a result of the short lifetime and fast diffusion rate of small ONOO , precise determination of the ONOO level at the cell surface remains a challenging task. In this paper, the use of a membrane-anchored streptavidin-biotin-controlled binding probe (CBP), ONOO-CBP, to determine quantitatively the ONOO level at the cell surface and to investigate the effect of different stimulants on the production of ONOO along the plasma membrane of macrophages is reported.

Target-activated streptavidin-biotin controlled binding probe.

Target-activated chemical probes are important tools in basic biological research and medical diagnosis for monitoring enzyme activities and reactive small molecules. Based on the fluorescence turn-on mechanism, they can be divided into two classes: dye-based fluorescent probes and caged-luciferin. In this paper, we introduce a new type of chemical probe in which the fluorescence turn-on is based on controlled streptavidin-biotin binding.