Johannes Franz

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Cell-penetrating peptides (CPPs) are short membrane-permeating amino acid sequences that can be used to deliver cargoes, e.g. drugs, into cells. The mechanism for CPP internalization is still subject of ongoing research. An interesting family of CPPs is the sweet arrow peptides - SAP(E) - which are known to adopt a polyproline II helical secondary(More)
Ovine brain glutamine synthetase (GS) utilizes various substituted glutamic acids as substrates. We have used this information to design alpha- and gamma-substituted analogues of phosphinothricin [L-2-amino-4-(hydroxymethylphosphinyl)butanoic acid], a naturally occurring inhibitor of GS. These compounds display competitive inhibition of GS, and a(More)
We have investigated the inhibition of Escherichia coli glutamine synthetase (GS) with alpha- and gamma-substituted analogues of phosphinothricin [L-2-amino-4-(hydroxymethylphosphinyl)butanoic acid (PPT)], a naturally occurring inhibitor of GS. These compounds display inhibition of bacterial GS that is competitive vs L-glutamate, with Ki values in the low(More)
Glutamine synthetase (GS) utilizes various substituted glutamic acids as substrates. We have used this information to design herbicidal alpha- and gamma-substituted analogs of phosphinothricin (l-2-amino-4-(hydroxymethylphosphinyl)butanoic acid, PPT), a naturally occurring GS inhibitor and a potent herbicide. The substituted phosphinothricins inhibit(More)
Nitrated fatty acids (NO2-FAs) act as anti-inflammatory signal mediators, albeit the molecular mechanisms behind NO2-FAs' influence on diverse metabolic and signaling pathways in inflamed tissues are essentially elusive. Here, we combine fluorescence measurements with surface-specific sum frequency generation vibrational spectroscopy and coarse-grained(More)
Cell-penetrating peptides (CPPs) are promising molecules as drug carriers. However, because their uptake mainly involves endocytic mechanisms, endosomal trapping of the carrier (and drug) remains a high barrier for biomedical applications. The viral fusion mimic GALA, a pH-triggered CPP, takes advantage of the decreasing pH during endosome maturation to(More)
Cationic amphiphilic peptides have been engineered to target both Gram-positive and Gram-negative bacteria while avoiding damage to other cell types. However, the exact mechanism of how these peptides target, bind, and disrupt bacterial cell membranes is not understood. One specific peptide that has been engineered to selectively capture bacteria is WLBU2(More)
Biophysical studies of the interaction of peptides with model membranes provide a simple yet effective approach to understand the transport of peptides and peptide based drug carriers across the cell membrane. Herein, the authors discuss the use of self-assembled monolayers fabricated from the full membrane-spanning thiol (FMST)(More)
Lipid monolayers are indispensable model systems for biological membranes. The main advantage over bilayer model systems is that the surface pressure within the layer can be directly and reliably controlled. The sensitive interplay between surface pressure and temperature determines the molecular order within a model membrane and consequently determines the(More)