Cytomegalovirus protease targeted prodrug development.

Area of Science:

• Virology
• Medicinal Chemistry
• Drug Development

Background:

• Human Cytomegalovirus (HCMV) is a widespread herpesvirus affecting up to 90% of the population.
• HCMV encodes a serine protease crucial for viral capsid assembly and replication.
• Developing targeted antiviral therapies remains a significant challenge.

Purpose of the Study:

• To investigate the potential of creating small molecular prodrugs activated specifically by the HCMV-encoded protease.
• To achieve site-specific activation of antiviral prodrugs, enhancing therapeutic efficacy and reducing off-target effects.
• To identify a selective prodrug strategy for HCMV infection.

Main Methods:

• Evaluated the esterase activity of a stable HCMV protease mutant (A143T/A144T) using model p-nitrophenol esters.
• Synthesized and tested monoamino acid and dipeptide prodrugs of ganciclovir (GCV) for hydrolysis by the HCMV protease mutant.
• Assessed prodrug hydrolysis in various biological matrices including cell homogenates, liver microsomes, and plasma to determine selectivity.

Main Results:

• The HCMV A143T/A144T protease mutant demonstrated esterase activity towards specific small ester compounds like Boc-L-Ala-ONp.
• A dipeptide prodrug of ganciclovir, Ac-l-Gln-l-Ala-GCV, was identified as a potential candidate for selective hydrolysis by the HCMV protease.
• The selectivity of prodrug hydrolysis was evaluated by comparing rates with HCMV protease versus host enzymes and plasma.

Conclusions:

• Targeted prodrug activation by the specific HCMV protease is a feasible strategy for antiviral therapy.
• The dipeptide prodrug Ac-l-Gln-l-Ala-GCV shows promise for selective activation by the HCMV protease.
• This approach could lead to novel therapeutic interventions against HCMV infections with improved specificity.