Biophysical Characterization of the Non-Fusogenic Interaction Between Liposomes and the Shrimp Bifunctional Lipoprotein-β-Glucan Binding Protein HDL/BGBP

Shrimp High Density Lipoprotein-β-Glucan Binding Protein (HDL/BGBP) has been studied by its role in nutrition and innate defense. Although the mechanisms of lipid loading are still unknown, HDL-BGBP binds and aggregates phospholipids vesicles in vitro. To gain insights into the HDL-BGBP mechanism of interaction with membranes, we have used fluorescence spectroscopy and electron microscopy. Data show that HDL-BGBP does not induce membrane fusion, leakage nor lipid exchange, although microstructural changes are clearly observed. This work supports a model where protein aggregation leads to liposome clustering. Such interaction may be a critical factor for the activation of the shrimp blood cell in vivo.