Potency assay (off target):
MT1 compound showed picomolar displacement of phage expressing:
BRD2(1): 160 pM;
BRD2(1,2): 24 pM;
BRD2(2): 33 pM;
BRD3(1):59 pM;
BRD3(1,2): 12 pM;
BRD3(2): 70 pM;
BRD4(1): 99 pM;
BRD4(1,2): 87 pM;
BRD4(2): 53 pM;
BRD4(full-length,short-iso.): 62 pM;
BRDT(1): 560 pM;
BRDT(1,2): 76 pM;
BRDT(2): 86 pM;
These dramatic increases in activity were confirmed to be selective for the BET family using a panel of 40 phage-displayed bromodomains (BROMOscan, DiscoverX). MT1 did not show significant binding to non-BET bromodomains at higher concentrations (IC50 = 1.8 μM for GCN5L2, 6.4 μM for CBP , 8.6 μM for EP300 and >10 μM for others:
ATAD2A
ATAD2B
BAZ2A
BAZ2B
BRD1
BRD7
BRD8(1)
BRD8(2)
BRD9
BRPF1
BRPF3
CECR2
FALZ
PBRM1(2)
PBRM1(5)
PCAF
SMARCA2
SMARCA4
TAF1(2)
TAF1L(2)
TRIM24(Bromo.)
TRIM24(PHD,Bromo.)
TRIM33(PHD,Bromo.)
WDR9(2)
Probe Selectivity in Vitro:
In ExpresSProfile (CEREP) MT1 showed negligible activity for over 50 ligand receptors, ion channels and transport proteins. Partial inhibition of the NK2 receptor was observed. Shown is %specific control bound radioligand when incubated with 1 uM MT1: Assay, [control ligand]: %specific bound control; VPAC1 (VIP1), [VIP]: 123.3; Y2, [NPY]: 117.05; Y1, [NPY]: 115; CB1, [CP 55940]: 112.95; CCR1, [MIP-1a]: 108.65; D2S, [(+)butaclamol]: 108.15; GAL2, [galanin]: 107.8; B2, [NPC 567]: 106.55; D1, [SCH 23390]: 105.95; 5-HT transporter, [imipramine]: 104.2; α1 (non-selective), [prazosin]: 102.95; 5-HT6, [serotonin]: 102.05; GABA (non-selective), [GABA]: 101.65; sst (non-selective), [somatostatin-14]: 101.45; α2 (non-selective), [yohimbine]: 101.35; µ (MOP), [DAMGO]: 100.5; CXCR2 (IL-8B), [IL-8]: 100.35; KV channel, [a-dendrotoxin]: 100.1; 5-HT1A, [8-OH-DPAT]: 99; BZD, [diazepam]: 97.3; MC4, [NDP-a-MSH]: 96.7; M2, [methoctramine]: 96.4; β1, [atenolol]: 96.25; Ca2+ channel (L, verapamil site) (phenylalkylamine), [D 600]: 96; κ (KOP), [U 50488]: 95.4; 5-HT3, [MDL 72222]: 94.65; NOP (ORL1), [nociceptin]: 94.35; 5-HT5a, [serotonin]: 94.2; 5-HT7, [serotonin]: 93.8; A2A, [NECA]: 93.8; NTS1 (NT1), [neurotensin]: 93.4; EP4, [PGE2]: 92.9; norepinephrine transporter, [protriptyline]: 92.9; 5-HT2A, [ketanserin]: 92.55; M1, [pirenzepine]: 92.25; SKCa channel, [apamin]: 92.1; V1a, [[d(CH2)51,Tyr(Me)2]-AVP]: 92.05; Na+ channel (site 2), [veratridine]: 91.85; β2, [ICI 118551]: 91.65; Cl- channel (GABA-gated), [picrotoxinin]: 90.5; ETA, [endothelin-1]: 90.5; 5-HT1B, [serotonin]: 90.45; dopamine transporter, [BTCP]: 89.85; M3, [4-DAMP]: 89.65; AT1, [saralasin]: 88; NK3, [SB 222200]: 87.6; 5-HT2B, [(±)DOI]: 87.45; MT1 (ML1A), [melatonin]: 86.8; H1, [pyrilamine]: 86.6; CCK1 (CCKA), [CCK-8s]: 82.95; δ2 (DOP), [DPDPE]: 81.05; A1, [DPCPX]: 79.05; H2, [cimetidine]: 77.55; A3, [IB-MECA]: 73.7; NK2, [[Nleu10]-NKA (4-10)]: 24.25;
Chemical Probes Portal MT1.pdf
