Rheem Totah

1. Introduction Thiopurine methyltransferase is a small molecule, S-adenosyl-methionine (SAM)-dependent methyltransferase [1]. TPMT is essential for the metabolism of immunosuppressive and antileukemic prodrugs azathioprine, 6-mercaptopurine (6-MP) (Figure 1), and thioguanine [1,2,3]. These prodrugs are converted to thioguanosine monophosphate (TGMP) in vivo, which is an antimetabolite that mimics guanosine monophosphate [4].

The IUPAC-Richter Prize was established in 2005 by the International Union of Pure and Applied Chemistry (IUPAC) and Richter PLC. On behalf of IUPAC, we are seeking nominations for the 2024 Award. The prize is awarded to an international recognized scientist, preferably a medicinal chemist, whose activities and published accounts have made an outstanding contribution to the practice of medicinal chemistry or the discovery of one or more new drugs.

Introduction: methyltransferases and the METTL family Methyltransferases are a critical class of highly evolutionarily conserved enzymes capable of exerting a wide range of regulatory effects through their ability to transfer a methyl group onto a substrate. The human genome is estimated to contain 208 genes encoding methyltransferases (1) where the majority of these contain the canonical Rossmann-fold S-adenosyl-L-methionine (SAM) binding domain (2, 3).