Table 3.

Binding properties of SPAK and OSR1 binding inhibitors.

Molecule	Chemical structure	Binding target (IC50)	Selectivity for target	Reference
Stock 1S-50699		SPAK (IC50 = 37,000 nM)	MAPK not inhibited at 200 μM.	[89]
Stock 2S-26016		SPAK (IC50 = 16,000 nM)	MAPK not inhibited at 200 μM. Non-inhibitory analog of Stock 2S-26016 did not affect SPAK and NCC phosphorylation.	[89]
ZT-1a (allosteric)		SPAK (IC50 = 40,500 nM) SPAK + MO25 (IC50 = 41,300 nM)	≥50% inhibition of 6/140 kinases (at 10 μM).	[71]
HK01		MO25 (IC50 = 78,000 ± 4000 nM)	MST3 not inhibited at 500 μM.	[90]