Related Experiment Videos
Glucan synthesis in Pneumocystis carinii
D J Williams1, J A Radding, A Dell
1MacArthur Center for Molecular Parasitology, Yale University School of Medicine, New Haven, Connecticut 06510.
The Journal of Protozoology
|July 1, 1991
Summary
Researchers discovered a glucan synthase enzyme in Pneumocystis carinii that produces an alpha 1-4 glucan polymer. This enzyme activity, crucial for understanding P. carinii metabolism, shows stability and high activity.
Area of Science:
- Biochemistry
- Mycology
- Parasitology
Background:
- Pneumocystis carinii is an opportunistic fungal pathogen responsible for pneumonia in immunocompromised individuals.
- Understanding the metabolic pathways of P. carinii is essential for developing targeted therapies.
Purpose of the Study:
- To investigate the enzymatic activity responsible for polymer synthesis in P. carinii.
- To characterize the nature of the synthesized polymer and the enzyme involved.
Main Methods:
- Pneumocystis carinii preparations were lysed using sodium deoxycholate.
- Enzyme activity was assessed by measuring the incorporation of uridine diphosphoglucose into insoluble polymers.
- Mass spectrometry was used to analyze the structure of the synthesized polymer.
- The effect of alpha amyloglucohydrolase on polymer formation was evaluated.
Main Results:
- Sodium deoxycholate-lysed P. carinii exhibited enzyme activity that incorporated uridine diphosphoglucose into an insoluble polymer.
- The polymer produced was identified as an alpha 1-4 glucan, with minimal branching.
- Polymer formation in the supernatant was completely inhibited by alpha amyloglucohydrolase, while pellet activity showed partial resistance.
- Soluble glucan synthase activity in the supernatant was stable at room temperature for over 30 hours and significantly more active than in Saccharomyces cerevisiae.
Conclusions:
- Pneumocystis carinii possesses a soluble glucan synthase activity capable of synthesizing alpha 1-4 glucan.
- This enzyme activity is distinct in its properties and substrate utilization compared to yeast glucan synthases.
- Further characterization of this enzyme could reveal novel targets for antifungal drug development against P. carinii infections.