A two-armed probe for in-cell DEER measurements on proteins

The application of double electron-electron resonance (DEER) with site-directed spin labeling (SDSL) to measure distances in proteins and protein complexes in living cells puts rigorous restraints on the spin-label. The linkage and paramagnetic centers need to resist the reducing conditions of the cell. Rigid attachment of the probe to the protein improves precision of the measured distances. Here, three two-armed GdIII complexes, GdIII-CLaNP13a/b/c were synthesized. Rather than the disulfide linkage of most other CLaNP molecules, a thioether linkage was used to avoid reductive dissociation of the linker. The doubly GdIII labeled N55C/V57C/K147C/T151C variants of T4Lysozyme were measured by 95 GHz DEER. The constructs were measured in vitro, in cell lysate and in Dictyostelium discoideum cells. Measured distances were 4.5 nm, consistent with results from paramagnetic NMR. A narrow distance distribution and typical modulation depth, also in cell, indicate complete and durable labeling and probe rigidity due to the dual attachment sites

Corrigendum: a two-armed probe for in-cell DEER measurements on proteins (vol 26, pg 17128, 2020)

CORRIGENDUM Q. Miao, E. Zurlo, D. de Bruin, J. A. J. Wondergem, S. P. Skinner, M. Timmer, A. Blok, D. Heinrich, M. Overhand, M. Huber,* M. Ubbink* 17128–17133 A Two-Armed Probe for In-Cell DEER Measurements on Proteins Chem. Eur. J., 2020, 26 DOI: 10.1002/chem.202002743 All authors have agreed that Dr. Simon P. Skinner has made a significant contribution to this work by performing experiments and analyzing data and that his name should have been included in the list of authors. The corrected list of authors therefore reads: Dr. Qing Miao, Dr. Enrico Zurlo, Donny de Bruin, Joeri A. J. Wondergem, Dr. Simon P. Skinner, Monika Timmer, Anneloes Blok, Prof. Dr. Doris Heinrich, Dr. Mark Overhand, Dr. Martina Huber, Prof. Dr. Marcellus Ubbink The relevant affiliations for Dr. Skinner are (1) Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333, CC Leiden, The Netherlands and (2) School of Molecular and Cellular Biology and Astbury Centre, University of Leeds, Leeds LS2 9JT, UK. The Acknowledgement section should not contain the sentence “and Dr. Simon Skinner for CLaNP5 labeled T4lys NMR data.Macromolecular Biochemistr

An adamantyl amino acid containing gramicidin S analogue with broad spectrum antibacterial activity and reduced hemolytic activity

et al.The cyclic cationic antimicrobial peptide gramicidin S (GS) is an effective topical antibacterial agent that is toxic for human red blood cells (hemolysis). Herein, we present a series of amphiphilic derivatives of GS with either two or four positive charges and characteristics ranging between very polar and very hydrophobic. Screening of this series of peptide derivatives identified a compound that combines effective antibacterial activity with virtually no toxicity within the same concentration range. This peptide acts against both Gram-negative and Gram-positive bacteria, including several MRSA strains, and represents an interesting lead for the development of a broadly applicable antibiotic. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Trabajo financiado por el Ministerio de España de Educación y Ciencia (número de concesión: BFU2008–01588) y Xunta de Galicia.Peer Reviewe

Gramicidin S derivatives containing cis- and trans-morpholine amino acids (MAAS) as turn mimetics

et al.The cyclic decapeptide gramicidin S (GS) was used as a model for the evaluation of four turn mimetics. For this purpose, one of the D-Phe-Pro two-residue turn motifs in the rigid cyclic β-hairp0in structure of GS was replaced with morpholine amino acids (MAA 2-5), differing in stereochemistry and length of the side-chain. The conformational properties of the thus obtained GS analogues (6-9) was assessed by using NMR spectroscopy and X-ray crystallography, and correlated with their biological properties (antimicrobial and hemolytic activity). We show that compound 8, containing the dipeptide isostere trans-MAA 4, has an apparent high structural resemblance with GS and that its antibacterial activity against a panel of Gram positive and -negative bacterial strains is better than the derivatives 6, 7 and 9. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.Este trabajo ha sido financiado por una beca del Leiden Institute of Chemistry y por la subvención BFU2008-01588/BMC del Ministerio español de Ciencia e Innovación. José M. Otero ha sido apoyado económicamente por un contratro “Angeles Alvariño” de la Xunta de Galicia.Peer Reviewe