Complementary coiled coil forming lipidated peptides embedded in liposomal membranes are able to induce rapid, controlled, and targeted membrane fusion. Traditionally, such fusogenic liposomes are prepared by mixing lipids and lipidated peptides in organic solvent (e.g., chloroform). Here we prepared fusogenic liposomes in situ, i.e., by addition of a lipidated peptide solution to plain liposomes. As the lipid anchor is vital for the correct insertion of lipidated peptides into liposomal membranes, a small library of lipidated coiled coil forming peptides was designed in which the lipid structure was varied. The fusogenicity was screened using lipid and content mixing assays showing that cholesterol modified coiled coil peptides induced the most efficient fusion of membranes. Importantly, both lipid and content mixing experiments demonstrated that the in situ modification of plain liposomes with the cholesterol modified peptides yielded highly fusogenic liposomes. This work shows that existing membranes can be activated with lipidated coiled coil forming peptides, which might lead to highly potent applications such as the fusion of liposomes with cells.

In this work, we have investigated the activation process and structure of Ni-promoted Mo x W(1–x)S2/Al2O3 hydrodesulfurization (HDS) catalysts. Conversion of Mo and W oxides to the catalytically active MS2 (M = Mo, W) phase by sulfidation in gaseous H2S/H2 proceeded via different pathways, as found by XPS and EXAFS. The slower sulfidation kinetics of W on the alumina support formed NiMo x W(1–x) sulfides with a two-dimensional core–shell structure. Mo was mostly located in the core and W in the shell, as evidenced by EXAFS. Increasing the H2S/H2 pressure during sulfidation distributed Mo and W more homogeneously in the metal sulfide particles. This was attributed to the more favorable sulfidation of W under these conditions (i.e., below the temperature of MoS2 formation). Catalytic testing was consistent with these findings and demonstrated that a core–shell structure is the active phase in thiophene HDS (1 atm), whereas a homogeneously mixed MS2 phase catalyzes the HDS of dibenzothiophene at 40 bar. This is the first example of a core–shell structure in promoted Mo x W(1–x)S2 catalysts. Support interactions in the oxidic precursor, which affect the sulfidation kinetics, were determined to play a key role in the formation of these structures.

The field of electrochemistry promises solutions for the future energy crisis and environmental deterioration by developing optimized batteries, fuel-cells and catalysts. Combined with in situ Transmission Electron Microscope (TEM), it...

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