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PEGylating a bacteriophage endolysin inhibits its bactericidal activity
Gregory Resch1, Philippe Moreillon, Vincent A Fischetti
1Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA. gregory.resch@unil.ch.
AMB Express
|October 11, 2011
Summary
PEGylation, a method to extend protein half-life, failed to enhance the activity of bacteriophage endolysins (lysins) against Streptococcus pneumoniae. The PEGylation process inhibited the enzybiotic
Area of Science:
- Microbiology
- Biochemistry
- Drug Development
Background:
- Bacteriophage endolysins (lysins) are enzymes that degrade bacterial peptidoglycan, causing cell lysis.
- Lysins show therapeutic potential as enzybiotics against Gram-positive bacteria, including Streptococcus pneumoniae.
- Systemic administration of proteins like lysins results in rapid clearance from circulation, limiting their therapeutic efficacy.
Purpose of the Study:
- To investigate the efficacy of PEGylation in extending the in vivo half-life and maintaining the lytic activity of the bacteriophage lysin Cpl-1.
- To evaluate the impact of cysteine-specific PEGylation on the antimicrobial properties of Cpl-1 against Streptococcus pneumoniae.
Main Methods:
- Cpl-1 lysin mutants with an additional cysteine residue were generated for site-specific PEGylation.
- Cysteine-specific PEGylation was performed using polyethylene glycol (PEG) molecules of 10K and 40K molecular weights.
- In vitro lytic activity of native Cpl-1, mutant Cpl-1, and PEGylated Cpl-1 conjugates against Streptococcus pneumoniae was assessed.
Main Results:
- Successful cysteine-specific PEGylation of Cpl-1 mutants with PEG 10K and 40K was achieved.
- None of the PEGylated Cpl-1 conjugates retained significant in vitro lytic activity against Streptococcus pneumoniae.
- The introduction of the cysteine residue alone did not affect the antimicrobial activity of the mutant enzymes.
Conclusions:
- PEGylation, via a cysteine-specific strategy, inhibits the antimicrobial activity of bacteriophage lysin Cpl-1.
- This study suggests that cysteine-specific PEGylation is not a viable strategy for improving the in vivo half-life of bacteriophage endolysins as enzybiotics.
- The modular structure of most endolysins may present inherent challenges for PEGylation strategies aimed at enhancing their therapeutic potential.
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