observed. In certain, the sulfonamide group may possibly hardly Phe58 stabilized by the hydrophobic atmosphere createdfor TbDHFR-TS,Phe94, Leu97,TCMDCbe and Met55. CK1 Biological Activity similarly, to what was reported by Pro91, Leu90, docking of 143249 in and LmDHFR-TS model highlighted nofor TbDHFR-TS, docking of TCMDCPhe58 the Met55. Similarly, to what was reported relevant key polar make contact with or hydrophobic interactionin the LmDHFR-TS model highlighted no relevant crucial polar speak to or hydropho143249 (Figure 7c). Even when the sulfonamide moiety may well establish polar interactions with bic interaction (Figure 7c). Even when backbone of Met43, may establish polar diaminopyrimidine the Lys57 side chain and with all the the sulfonamide moietythe cyano-phenyl interactions corewith the Lys57 side chain and with the backbone of Met43, the cyano-phenyl diaminopymisses the donor/acceptor requirements that stabilize the pteridine substrate. These rimidine core misses the findings point towards a donor/acceptor needs that stabilize the Tb- and LmDHFR-TS, most likely instability of TCMDC-143249 in pteridine substrate. These findings point towards a probably instability of TCMDC-143249 in Tb- and therefore delivering a structural basis for thebasis for the differentialof TCMDC-143249 in PTR1 differential activity activity of TCMDCLmDHFR-TS, therefore providing a structural and 143249 in PTR1 enzymes. in DHFR-TS and in DHFR-TS enzymes.abcFigure 7.Figure 7. TCMDC-143249 docking poses in Tband LmDHFR (a). Pyrimethamine inhibitor (white) key polar contacts in contacts TCMDC-143249 docking poses in Tb and LmDHFR (a). Pyrimethamine inhibitor (white) key polar PDB ID 3RG9. Docking pose of TCMDC-143249 (magenta) in TbDHFR (b), and in LmDHFR model (c). Protein is reprein PDB ID 3RG9.cartoon (TbDHFR, light green; LmDHFR, violet), with relevant binding web site and in LmDHFR model (c). Protein is sented as Docking pose of TCMDC-143249 (magenta) in TbDHFR (b), residues depicted as sticks and labelled. cartoon (TbDHFR, light green; LmDHFR, capped with For clarity, polar hydrogens are shown for ligands represented as NADPH cofactor (cyan) and ligands are shown asviolet), sticks. relevant binding web site residues depicted as sticks and labelled.only. NADPH cofactor (cyan) and ligands are shown as capped sticks. For clarity, polar hydrogens are shown for ligands only.The other compounds indicated in Table 4 offer much less helpful inhibition and primarily drop the pan-inhibitor profile. TCMDC-143191 shows an fascinating activity only towards TbPTR1 and EZH2 Source assumes an orientation unique from each the antifolate- and substrate-like ones, in which the pyrimidine nitrogen H-bonds Tyr174 along with the ribose, the tricyclic program types a hydrophobic interaction with Trp221 plus the carbonyl contacts Cys168 (Figure S4a). Compound TCMDC-143459 behaves similarly, displaying an effect only towards TbPTR1 and being able to profitably locate only in PDB ID 4CLO, where it H-binds to NADPH ribose and phosphates via the triazole and imidazole rings, andPharmaceuticals 2021, 14,14 ofThe other compounds indicated in Table four present less efficient inhibition and primarily drop the pan-inhibitor profile. TCMDC-143191 shows an intriguing activity only towards TbPTR1 and assumes an orientation different from both the antifolate- and substrate-like ones, in which the pyrimidine nitrogen H-bonds Tyr174 and the ribose, the tricyclic system types a hydrophobic interaction with Trp221 along with the carbonyl contacts Cys168 (Figure S4a). Compound TCMDC-143