Bisubstrate analogue inhibitors of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase: New design with improved properties

Bioorg Med Chem. 2012 Jan 1;20(1):47-57. doi: 10.1016/j.bmc.2011.11.032. Epub 2011 Nov 23.


6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK), a key enzyme in the folate biosynthetic pathway, catalyzes the pyrophosphoryl transfer from ATP to 6-hydroxymethyl-7,8-dihydropterin. The enzyme is essential for microorganisms, is absent from humans, and is not the target for any existing antibiotics. Therefore, HPPK is an attractive target for developing novel antimicrobial agents. Previously, we characterized the reaction trajectory of HPPK-catalyzed pyrophosphoryl transfer and synthesized a series of bisubstrate analog inhibitors of the enzyme by linking 6-hydroxymethylpterin to adenosine through 2, 3, or 4 phosphate groups. Here, we report a new generation of bisubstrate analog inhibitors. To improve protein binding and linker properties of such inhibitors, we have replaced the pterin moiety with 7,7-dimethyl-7,8-dihydropterin and the phosphate bridge with a piperidine linked thioether. We have synthesized the new inhibitors, measured their K(d) and IC(50) values, determined their crystal structures in complex with HPPK, and established their structure-activity relationship. 6-Carboxylic acid ethyl ester-7,7-dimethyl-7,8-dihydropterin, a novel intermediate that we developed recently for easy derivatization at position 6 of 7,7-dimethyl-7,8-dihydropterin, offers a much high yield for the synthesis of bisubstrate analogs than that of previously established procedure.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Binding Sites
  • Computer Simulation
  • Crystallography, X-Ray
  • Diphosphotransferases / antagonists & inhibitors*
  • Diphosphotransferases / metabolism
  • Drug Design*
  • Enzyme Activation / drug effects
  • Enzyme Inhibitors / chemical synthesis
  • Enzyme Inhibitors / chemistry*
  • Enzyme Inhibitors / pharmacology
  • Kinetics
  • Molecular Conformation
  • Protein Structure, Tertiary
  • Pterins / chemical synthesis
  • Pterins / chemistry*
  • Pterins / pharmacology
  • Structure-Activity Relationship
  • Substrate Specificity


  • 6-hydroxymethyl-7,8-dihydropterin
  • Anti-Bacterial Agents
  • Enzyme Inhibitors
  • Pterins
  • Diphosphotransferases

Associated data

  • PDB/3UD5
  • PDB/3UDE
  • PDB/3UDV