Cellular Metabolic Network Analysis: Discovering Important Reactions inTreponema pallidum

Abstract

T. pallidum, the syphilis-causing pathogen, performs very differently in metabolism compared with other bacterial pathogens. The desire for safe and effective vaccine of syphilis requests identification of important steps inT. pallidum’s metabolism. Here, we apply Flux Balance Analysis to represent the reactions quantitatively. Thus, it is possible to cluster all reactions inT. pallidum. By calculating minimal cut sets and analyzing topological structure for the metabolic network ofT. pallidum, critical reactions are identified. As a comparison, we also apply the analytical approaches to the metabolic network ofH. pylorito find coregulated drug targets and unique drug targets for different microorganisms. Based on the clustering results, all reactions are further classified into various roles. Therefore, the general picture of their metabolic network is obtained and two types of reactions, both of which are involved in nucleic acid metabolism, are found to be essential forT. pallidum. It is also discovered that both hubs of reactions and the isolated reactions in purine and pyrimidine metabolisms play important roles inT. pallidum. These reactions could be potential drug targets for treating syphilis.