Skip to main content
. Author manuscript; available in PMC: 2021 Aug 18.
Published in final edited form as: Acc Chem Res. 2020 Jul 21;53(8):1593–1604. doi: 10.1021/acs.accounts.0c00292

Figure 4.

Figure 4.

NP-EGTA - the first highly effective, cation-selective caged calcium.

A. Synthesis of NP-EGTA19. B. Fluorescence from the Ca2+ indicator fluo-3 with NP-EGTA, but before adding any Ca2+ (cyan). NP-EGTA is a high affinity Ca2+ cage (blue) that is Ca2+-specific (mustard dashes), and releases large quantities of Ca2+ upon photolysis (pink). The chelation and uncaging of Ca2+ by NP-EGTA is illustrated on the right. C. Single channel currents from RyR of black lipid membranes. Uncaging NP-EGTA in absence (i) or presence of 1 mM Mg2+ (ii & iii), step increases in [Ca2+]free to 1 μM (i) or 10 μM (ii & iii) caused rapid opening of the Ca2+ channels. The presence of Mg2+ caused a rapid adaption of the open channel probability (PO) as shown in (iv). C: Reproduced with permission from ref. 21. Copyright (1995) AAAS.