discovery of the potent NTMT1 bisubstrate inhibitor NAM-C3-PKRIA-NH2 that exhibits greater than 100fold selectivity against a panel of methyltransferases. Crystal structure analysis of NTMT1 in complex with the inhibitor reveals that NAM-C3-PKRIA-NH2 occupies substrate and cofactor binding sites of NTMT1
the inhibitor is enzyme-specific with a competitive inhibition pattern for both substrates, selective versus protein lysine methyltransferase G9a and arginine methyltransferase 1. The inhibitor substantially suppresses the methylation progression. The sulfur is replaced with a less reactive nitrogen to yield N-adenosyl-L-methionine as a stable analogue of S-adenosyl-L-methionine. Hexapeptide SPKRIA is derived from the N-terminus of regulator of chromosome condensation 1, RCC1. Binding structure modeling using the crystal structure of NTMT1 with S-adenosyl-L-homocysteine, PDB ID 2EX4. The two parts are connected via the triazole linker. NAM-TZ-SPKRIA acts as a competitive inhibitor when the concentration of S-adenosyl-L-methionine is varied from 0.003-0.010 mM and RCC1-10 substrate peptide is at a fixed concentration at 0.003 mM
feasibility of using a triazole group to link an S-adenosyl-L-methionine analogue with a peptide substrate to construct bisubstrate analogues as NTMT1 potent and selective inhibitors, a general strategy for the development of selective protein methyltransferase inhibitors
development of potent and specific inhibitors, bisubstrate analogues that simultaneously target both binding sites are proven to be an effective strategy to obtain potent and selective inhibitors for many enzymes with two binding sites. Because NTMT1 forms a ternary complex during catalysis, a bisubstrate strategy has been applied to design and synthesize bisubstrate inhibitors by covalently linking a SAM analogue with a peptide substrate to mimic the transition state. NTMT1 bisubstrate inhibitors contain three components: an N-adenosyl-L-methionine (NAM) that replaces the sulfonium ion of SAM with a nitrogen atom, a hexapeptide derived from the N-terminal sequence of NTMT1 substrate, and a linker. The potency of such bisubstrate inhibitors corroborate the Bi Bi mechanism of NTMT1 methylation
development of potent and specific inhibitors, bisubstrate analogues that simultaneously target both binding sites are proven to be an effective strategy to obtain potent and selective inhibitors for many enzymes with two binding sites. Because NTMT1 forms a ternary complex during catalysis, a bisubstrate strategy has been applied to design and synthesize bisubstrate inhibitors by covalently linking a SAM analogue with a peptide substrate to mimic the transition state. NTMT1 bisubstrate inhibitors contain three components: an N-adenosyl-L-methionine (NAM) that replaces the sulfonium ion of SAM with a nitrogen atom, a hexapeptide derived from the N-terminal sequence of NTMT1 substrate, and a linker. The potency of such bisubstrate inhibitors corroborate the Bi Bi mechanism of NTMT1 methylation