Mechanism involved in HAMLET induced bacterial death

In this project , we will elucidate the mechanism of HAMLET (a human milk protein-lipid complex) induced bactericidal activity using Streptococcus pneumoniae as a model organism. HAMLET kills certain bacteria through an apoptosis-like pathway that is separate from current antibiotic classes. Prior data has indicated that HAMLET interacts with the cell surface, induces depolarization and ion fluxes over the bacterial membrane that blocks glycolysis and ATP production and initiates bacterial death executed through activation of a potential Ser/Thr kinase. This indicates that HAMLET activates a death pathway(s) that has not been previously characterized, and this pathway include many key components, which are important also during the normal physiological life cycle of the organism.In these studies, the goal is to study in detail the interaction of HAMLET with the bacterial surface; both the cell wall and its components and interactions with the membrane will be investigated. Furthermore, the trigger and execution of bacterial death will be studied. We know that HAMLET binding leads to dissipation of the protein motive force that involves direct interactions with the F-type hydrogen ATPase. This leads to an increase in the intracellular calcium levels that activate a Ser/The kinase that has not been characterized. Studies to characterize the interaction with the H+ATPase and the activation of the Ser/Thr kinase (StkX) will be part of the thesis. Finally, HAMLET has been shown to also bind and inhibit two central enzymes in glycolysis and block ATP production. Understanding the activation of bacterial death by HAMLET will allow the identification of antibacterial targets for future therapy with less risk for antibiotic resistance development.