New antibiotics are urgently needed to address multidrug-resistant (MDR) bacteria. Herein we report that second-generation (G2) peptide dendrimers bearing a fatty acid chain at the dendrimer core efficiently kill Gram-negative bacteria including Pseudomonas aeruginosa and Acinetobacter baumannii, two of the most problematic MDR bacteria worldwide. Our most active dendrimer TNS18 is also active against Gram-positive methicillin-resistant Staphylococcus aureus. Based on circular dichroism and molecular dynamics studies, we hypothesize that TNS18 adopts a hydrophobically collapsed conformation in water with the fatty acid chain backfolded onto the peptide dendrimer branches and that the dendrimer unfolds in contact with the membrane to expose its lipid chain and hydrophobic residues, thereby facilitating membrane disruption leading to rapid bacterial cell death. Dendrimer TNS18 shows promising in vivo activity against MDR clinical isolates of A. baumannii and Escherichia coli, suggesting that lipidated peptide dendrimers might become a new class of antibacterial agents.

We used nearest-neighbor searches in chemical space to improve the activity of the antimicrobial peptide dendrimer (AMPD) G3KL and identified dendrimer T7, which has an expanded activity range against Gram-negative pathogenic bacteria including Klebsiellae pneumoniae, increased serum stability, and promising activity in an in vivo infection model against a multidrug-resistant strain of Acinetobacter baumannii. Imaging, spectroscopic studies, and a structural model from molecular dynamics simulations suggest that T7 acts through membrane disruption. These experiments provide the first example of using virtual screening in the field of dendrimers and show that dendrimer size does not limit the activity of AMPDs.

We used the concept of chemical space to explore a virtual library of bicyclic peptides formed by double thioether cyclization of a precursor linear peptide, and identified an antimicrobial bicyclic peptide (AMBP) with remarkable activity against several MDR strains of Acinetobacter baumannii and Pseudomonas aeruginosa.

A new family of cyclic antimicrobial peptides is reported targeting multidrug resistant Pseudomonas aeruginosa by membrane disruption.

Charge transport across the peptide chains is one of the vital processes in the biological systems, so understanding their charge transport properties is an indispensable prerequisite to explain the complex biochemical phenomenon. Here, we review the charge transport mechanism, the influence of the special groups and the experimental conditions on the charge transport through the peptide backbone by employing the single-molecule electrical measurements. Besides, we further review the recent progresses in charge transport properties of supramolecular interaction among the adjacent peptide chains. Finally, we discuss some experimental and theoretical contradictions existing in the charge transport through peptides and provide new inspiration for the future development of the bioelectronics at the single-molecule scale.Haining Zheng (left) received her BEng Degree from Qingdao University of Science and Technology in 2017. She is currently pursuing her master degree under the supervision of Prof. Wenjing Hong in Xiamen University. Her research interests include the charge transport through peptidesupramolecular interaction network and quantum interference effects of perovskite quantum dots in single-molecule scale.Feng Jiang (middle) received his BEng Degree from Qingdao University of Science and Technology in 2017. He is currently a master student under the supervision of Prof. Wenjing Hong at Xiamen University, where he is interested in the quantum interference effects in singlemolecule electronics.Prof. Wenjing Hong has been a full professor in State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering in Xiamen University. He obtained a Ph.D. degree in 2013 from the University of Bern, Switzerland under supervision of Prof. Thomas Wandlowski. His current research is mainly focused on single-molecule electronics, the applications of artificial intelligence for chemistry and chemical engineering.

We used nearest‐neighbor searches in chemical space to improve the activity of the antimicrobial peptide dendrimer (AMPD) G3KL and identified dendrimer T7, which has an expanded activity range against Gram‐negative pathogenic bacteria including Klebsiellae pneumoniae, increased serum stability, and promising activity in an in vivo infection model against a multidrug‐resistant strain of Acinetobacter baumannii. Imaging, spectroscopic studies, and a structural model from molecular dynamics simulations suggest that T7 acts through membrane disruption. These experiments provide the first example of using virtual screening in the field of dendrimers and show that dendrimer size does not limit the activity of AMPDs.