| Abstract: | ABSTRACT. The binding of synthetic peptides modeled from the sequence of the cell attachment site of fibronectin to T. cruzi trypomastigote surface receptors was investigated by fluorescence-activated cell-sorting analysis using fluorescein-labeled peptides. Peptides with the sequence Arg-Gly-Asp-Ser bound to the parasite surface. A low percentage of fresh parasites recently liberated from infected fibroblasts had the capacity to bind the peptide. In contrast, these parasites showed a time-dependent several-fold increase in their ability to bind the Arg-Gly-Asp-Ser-containing peptides during extracellular incubation. From these observations, it appears that the expression of surface receptors on a particular, mature stage of the parasite parallels its ability to adhere to and infect host cells. |
