The human intermediate conductance calcium-activated potassium channel, KCa3.1, is involved in
several pathophysiological conditions playing a critical role in cell secretory machinery and calcium signalling.
The recent cryo-EM analysis provides new insights for understanding the modulation by both endogenous and
pharmacological agents. A typical feature of this channel is the low open probability in saturating calcium concentrations
and its modulation by potassium channel openers (KCOs), such as benzo imidazolone 1-EBIO, without
changing calcium-dependent activation. In this paper, we proposed a model of KCOs action in the modulation
of channel activity. The KCa3.1 channel has a very rich pharmacological profile with several classes of molecules
that selectively interact with different binding sites of the channel. Among them, benzo imidazolones can be
openers (positive modulators such as 1-EBIO, DC-EBIO) or blockers (negative modulators such as NS1619).
Through computation modelling techniques, we identified the 1,4-benzothiazin-3-one as a promising scaffold to
develop new KCa3.1 channel modulators. Further studies are needed to explore the potential use of 1-4 benzothiazine-
3-one in KCa3.1 modulation and its pharmacological application.
In Vivo Evidence for Nitric Oxide–Mediated Calcium-Activated Potassium-Channel Activation During Human Endotoxemia