FM-381 is a JAK3 specific reversible covalent inhibitor with IC50 of 127 pM for JAK3 and demonstrates 400-, 2,700- and 3,600-fold selectivity over JAK1, JAK2, and TYK2, respectively.

＞98%

Store at -20℃ for one year（Powder）；Store at 2-4℃ for two weeks；Store at -20℃ for six months after dissolution.

FM 381；FM381

Powder

DMSO : 12.8 mg/mL (29.87 mM; Need ultrasonic and warming)

JAK3

FM-381 is a potent covalent reversible inhibitor of JAK3 targeting the unique Cys909 at the gatekeeper (GK) position +7 in JAK3 exhibited apparent JAK3 IC50 values of 0.127 nM, with 400-, 2700- and 3600-fold selectivity over JAK1, JAK2 and TYK2, respectively. FM-381 was found to be inactive in a selectivity panel of frequently hit BRDs (BRD4, BRPF, CECR, FALZ, TAF1, BRD9). FM-381 shows an apparent EC50 of 100 nM in a dose dependent BRET assay and blocks IL2-stimulated (JAK3/JAK1 dependent) STAT5 phosphorylation at 100 nM, but not JAK3 independent IL6-stimulated (JAK1/2/TYK dependent) STAT3 signalling in Human CD4+ T cells up to 1 µM.