Cytomegalovirus protease targeted prodrug development

Mol Pharm. 2013 Apr 1;10(4):1417-24. doi: 10.1021/mp3007067. Epub 2013 Mar 20.

Abstract

Human cytomegalovirus (HCMV) is a prevalent virus that infects up to 90% of the population. The goal of this research is to determine if small molecular prodrug substrates can be developed for a specific HCMV encoded protease and thus achieve site-specific activation. HCMV encodes a 256 amino acid serine protease that is responsible for capsid assembly, an essential process for herpes virus production. The esterase activity of the more stable HCMV A143T/A144T protease mutant was evaluated with model p-nitrophenol (ONp) esters, Boc-Xaa-ONp (Ala, Leu, Ile, Val, Gln, Phe at the Xaa position). We demonstrate that the A143T/A144T mutant has esterase activity toward specific small ester compounds, e.g., Boc-L-Ala-ONp. Mono amino acid and dipeptide prodrugs of ganciclovir (GCV) were also synthesized and evaluated for hydrolysis by the A143T/A144T protease mutant in solution. Hydrolysis of these prodrugs was also evaluated in Caco-2 cell homogenates, human liver microsomes (HLMs), and rat and human plasma. For the selectivity potential of the prodrugs, the hydrolysis ratio was evaluated as a percentage of prodrug hydrolyzed by the HCMV protease over the percentages of prodrug hydrolyses by Caco-2 cell homogenates, HLMs, and human/rat plasma. A dipeptide prodrug of ganciclovir, Ac-l-Gln-l-Ala-GCV, emerged as a potential selective prodrug candidate. The results of this research demonstrate that targeting prodrugs for activation by a specific protease encoded by the infectious HCMV pathogen may be achievable.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antiviral Agents / chemistry
  • Antiviral Agents / pharmacology
  • Caco-2 Cells
  • Cloning, Molecular
  • Cytomegalovirus / enzymology*
  • Drug Delivery Systems
  • Drug Design*
  • Esters / chemistry
  • Ganciclovir / chemistry
  • Ganciclovir / pharmacology
  • Humans
  • Hydrolysis
  • Kinetics
  • Microsomes, Liver / drug effects
  • Microsomes, Liver / metabolism
  • Models, Chemical
  • Mutation
  • Peptide Hydrolases / chemistry*
  • Prodrugs / chemistry
  • Prodrugs / metabolism*
  • Rats
  • Temperature

Substances

  • Antiviral Agents
  • Esters
  • Prodrugs
  • Peptide Hydrolases
  • Ganciclovir