Peptidomimetic Inhibitors of the Human Cytomegalovirus Protease
摘要:
The development of peptidomimetic inhibitors of the human cytomegalovirus (HCMV) :protease showing sub-micromolar potency in an enzymatic assay is described. Selective substitution of the amino acid residues of these inhibitors led to the identification of tripeptide inhibitors showing improvements in inhibitor potency cf 27-fold relative to inhibitor 39 based upon the natural tetrapeptide sequence. Small side chains at P-1 were well tolerated by this enzyme, a fact consistent with previous observations. The S-2 binding pocket of HCMV protease was very permissive, tolerating lipophilic and basic residues. The substitutions tried at P-3 indicated that a small increase in inhibitor potency could be realized by the substitution of a tert-leucine residue for valine. Substitutions of the N-terminal capping group did not significantly affect inhibitor potency. Pentafluoroethyl ketones, alpha,alpha-difluoro-beta-keto amides, phosphonates and a-keto amides were all effective substitutions for the activated carbonyl component and gave inhibitors which were selective for HCMV protease. A slight increase in potency was observed by lengthening the P-1' residue of the alpha-keto amide series of inhibitors. This position also tolerated a variety of groups making this a potential site for future modifications which could modulate the physicochemical properties of these molecules.