High throughput selection of effective serodiagnostics for Trypanosoma cruzi infection.

Background: Diagnosis of Trypanosoma cruzi infection by direct pathogen detection is complicated by the low parasite burden in subjects persistently infected with this agent of human Chagas disease. Determination of infection status by serological analysis has also been faulty, largely due to the lack of well-characterized parasite reagents for the detection of anti-parasite antibodies.

Methods: In this study, we screened more than 400 recombinant proteins of T.

Benzoate decreases the binding of cis,cis-muconate to the BenM regulator despite the synergistic effect of both compounds on transcriptional activation.

Fluorescence emission spectroscopy was used to investigate interactions between two effectors and BenM, a transcriptional regulator of benzoate catabolism. BenM had a higher affinity for cis,cis-muconate than for benzoate as the sole effector. However, the presence of benzoate increased the apparent dissociation constant (reduced the affinity) of the protein for cis,cis-muconate.

Synergistic transcriptional activation by one regulatory protein in response to two metabolites.

BenM is a LysR-type bacterial transcriptional regulator that controls aromatic compound degradation in Acinetobacter sp. ADP1. Here, in vitro transcription assays demonstrated that two metabolites of aromatic compound catabolism, benzoate and cis,cis-muconate, act synergistically to activate gene expression.