2020-08-27, Di Girolamo, Salvatore, Puorger, Chasper, Lipps, Georg

2016-04-26, Lipps, Georg

Recent research has demonstrated that all body fluids assessed contain substantial amts. of vesicles that range in size from 30 to 1000 nm and that are surrounded by phospholipid membranes contg. different membrane microdomains such as lipid rafts and caveolae. The most prominent representatives of these so-​called extracellular vesicles (EVs) are nanosized exosomes (70-​150 nm)​, which are derivs. of the endosomal system, and microvesicles (100-​1000 nm)​, which are produced by outward budding of the plasma membrane. Nanosized EVs are released by almost all cell types and mediate targeted intercellular communication under physiol. and pathophysiol. conditions. Contg. cell-​type-​specific signatures, EVs have been proposed as biomarkers in a variety of diseases. Furthermore, according to their phys. functions, EVs of selected cell types have been used as therapeutic agents in immune therapy, vaccination trials, regenerative medicine, and drug delivery. Undoubtedly, the rapidly emerging field of basic and applied EV research will significantly influence the biomedicinal landscape in the future. In this Perspective, we, a network of European scientists from clin., academic, and industry settings collaborating through the H2020 European Cooperation in Science and Technol. (COST) program European Network on Microvesicles and Exosomes in Health and Disease (ME-​HAD)​, demonstrate the high potential of nanosized EVs for both diagnostic and therapeutic (i.e., theranostic) areas of nanomedicine.

2019, Di Girolamo, Salvatore, Lipps, Georg

Sortase enzymes play an important role in Gram-positive bacteria. They are responsible for the covalent attachment of proteins to the surface of the bacteria and perform this task via a highly sequence-specific transpeptidation reaction. Since these immobilized proteins are often involved in pathogenicity of Gram-positive bacteria, characterization of this type of enzyme is also of medical relevance. Different classes of sortases (A-F) have been found, which recognize characteristic recognition sequences present in substrate proteins. Up to date, sortase A from Staphylococcus aureus, a housekeeping class A sortase, is the most thoroughly studied representative of the sortase family of enzymes. Here we report the in-depth characterization of the class F sortase from Propionibacterium acnes, a class of sortases that has not been investigated before. As Sortase F is the only transpeptidase found in the P. acnes genome, it is the housekeeping sortase of this organism. Sortase F from P. acnes shows a behavior similar to sortases from class A in terms of pH dependence, recognition sequence and catalytic activity; furthermore, its activity is independent of bivalent ions, which contrasts to sortase A from S. aureus We demonstrate that sortase F is useful for protein engineering applications, by producing a site-specifically conjugated homogenous antibody-drug conjugate with a potency similar to that of a conjugate prepared with sortase A. Thus, the detailed characterization presented here will not only enable the development of anti-virulence agents targeting P. acnes but also provides a powerful alternative to sortase A for protein engineering applications. © 2019 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

2015-05-14, Lipps, Georg

2018-12-27, Boudet, Julien, Devillier, Jean-Christophe, Lipps, Georg

2015-05-02, Boudet, Julien, Devillier, Jean-Christophe, Allain, Frédéric H.-T., Lipps, Georg