Biology subjects

Noinaj, N.

Publications and source records attributed to Noinaj, N..

2 recordsLinked to original sources

bioRxiv2020

Probing the Plasticity in the Active Site of Protein N-terminal Methyltransferase 1 Using Bisubstrate Analogs

The interactions of a series of bisubstrate analogs with protein N-terminal methyltransferase 1 (NTMT1) were examined to probe the molecular properties of the NTMT1 active site through biochemical characterization and structural studies. Our results indicate that a 2-C to 4-C atom linker enables its respective bisubstrate analog to occupy both substrate and cofactor binding sites of NTMT1, but the bisubstrate analog with a 5-C atom linker only interacts with the substrate binding site and functions as a substrate. Furthermore, the 4-C atom linker is the optimal and produces the most potent inhibitor (Ki, app = 130 {+/-} 40 pM) for NTMT1 to date, displaying over 100,000-fold selectivity over other methyltransferases and 3,000-fold even to its homolog NTMT2. This study reveals the molecular basis for the plasticity of the NTMT1 active site. Additionally, our study outlines a general guidance on the development of bisubstrate inhibitors for any methyltransferases.

biochemistry↗

bioRxiv2020

Selective Peptidomimetic Inhibitors of NTMT1/2: Rational design, synthesis, characterization, and crystallographic studies

Protein N-terminal methyltransferases (NTMTs) methylate the -N-terminal amines of proteins starting with the canonical X-P-K/R motif. Genetic studies imply that NTMT1 regulates cell mitosis and DNA damage repair. Herein, we report the rational design and development of the first potent peptidomimetic inhibitors for NTMT1. Biochemical and co-crystallization studies manifest that BM30 (IC50 of 0.89 {+/-} 0.10 {micro}M) is a competitive inhibitor to the peptide substrate and noncompetitive to the cofactor S-adenosylmethionine. BM30 exhibits over 100-fold selectivity to NTMT1/2 among a panel of 41 methyltransferases, indicating the potential to achieve high selectivity when targeting the peptide substrate binding site of NTMT1/2. Its cell-permeable analog DC432 (IC50 of 54 {+/-} 4 nM) decreases the N-terminal methylation level of SET protein in HCT116 cells. This proof-of principle study provides valuable probes for NTMT1/2 and highlights the opportunity to develop more cell-potent inhibitors to elucidate the function of NTMTs in future.

biochemistry↗