Related Experiment Video
Updated: Apr 20, 2026
Development of a Quantitative Recombinase Polymerase Amplification Assay with an Internal Positive Control
Published on: March 30, 2015
Target validation of the inosine monophosphate dehydrogenase (IMPDH) gene in Cryptosporidium using Phylomer(®)
R Jefferies1, R Yang2, C K Woh1
1School of Veterinary and Life Sciences, Murdoch University, Western Australia, Australia; Phylogica, Telethon Institute for Child Health Research, Subiaco, Western Australia, Australia.
Abstract:
Cryptosporidiosis, a gastroenteric disease characterised mainly by diarrheal illnesses in humans and mammals is caused by infection with the protozoan parasite Cryptosporidium. Treatment options for cryptosporidiosis are limited, with the current therapeutic nitazoxanide, only partly efficacious in immunocompetent individuals. The parasite lacks de novo purine synthesis, and is exclusively dependant on purine salvage from its host. Inhibition of the inosine 5' monophosphate dehydrogenase (IMPDH), a purine salvage enzyme that is essential for DNA synthesis, thereby offers a potential drug target against this parasite. In the present study, a yeast-two-hybrid system was used to identify Phylomer peptides within a library constructed from the genomes of 25 phylogenetically diverse bacteria that targeted the IMPDH of Cryptosporidium parvum (IMPcp) and Cryptosporidium hominis (IMPch). We identified 38 unique interacting Phylomers, of which, 12 were synthesised and screened against C. parvum in vitro. Two Phylomers exhibited significant growth inhibition (81.2-83.8% inhibition; P < 0.05), one of which consistently exhibited positive interactions with IMPcp and IMPch during primary and recapitulation yeast two-hybrid screening and did not interact with either of the human IMPDH proteins. The present study highlightsthe potential of Phylomer peptides as target validation tools for Cryptosporidium and other organisms and diseases because of their ability to bind with high affinity to target proteins and disrupt function.
Insights
Researchers identified novel Phylomer peptides that inhibit Cryptosporidium parasite growth by targeting essential enzymes. These peptides show potential as new therapeutic leads for cryptosporidiosis, a diarrheal disease with limited treatment options.
Area of Science:
- Parasitology
- Drug Discovery
- Molecular Biology
Background:
- Cryptosporidiosis is a diarrheal illness caused by the parasite Cryptosporidium, with limited treatment options.
- The parasite relies on host purines for survival, making purine salvage enzymes like IMPDH a potential drug target.
- Current treatments like nitazoxanide have limited efficacy.
Purpose of the Study:
- To identify novel therapeutic agents targeting Cryptosporidium by exploring Phylomer peptides.
- To investigate the potential of inhibiting the parasite's purine salvage pathway.
Main Methods:
- A yeast-two-hybrid system was employed to screen a bacterial genome library for Phylomer peptides targeting Cryptosporidium IMPDH (IMPcp and IMPch).
- Identified Phylomers were synthesized and tested in vitro for their ability to inhibit C. parvum growth.
- Specificity was assessed by testing interactions with human IMPDH proteins.
Main Results:
- 38 unique Phylomer peptides interacting with IMPcp and IMPch were identified.
- Two synthesized Phylomers demonstrated significant in vitro growth inhibition of C. parvum (81.2-83.8%).
- One Phylomer showed specific interaction with parasite IMPDH, not human IMPDH.
Conclusions:
- Phylomer peptides represent a promising new class of compounds for targeting Cryptosporidium.
- These peptides can serve as valuable tools for target validation in parasitic diseases.
- The identified Phylomers offer potential as leads for developing new anti-cryptosporidial therapies.
