document

Expression of virulence and antimicrobial related proteins in Burkholderia mallei and Burkholderia pseudomallei

Paauw, A. (author), Scholz, H.C. (author), Mars-Groenendijk, R.H. (author), Dekker, L.J.M. (author), Luider, T.M. (author), Leeuwen, H.C. (author)

Meliodosis and glanders are both potential biological threat agents. Glanders is endemic in Southeast Asia and Northern Australia but occasionally found in other countries. Meliodosis is caused by Burkholderia pseudomallei, while glanders is caused by Burkholderia mallei. The diagnosis of these diseases is difficult because the clinical picture...

article 2023

document

Combining CRISPR–Cas12a with terminal deoxynucleotidyl transferase dependent reporter elongation for pathogen detection using lateral flow test strips

Berghuis, N.F. (author), Mars-Groenendijk, R.H. (author), Busker, R.W. (author), Paauw, A. (author), van Leeuwen, H.C. (author)

CRISPR–Cas (CC)-based detection technologies have some exceptional features, which hold the promise of developing into the nextgeneration diagnostic platforms. One of these features is the ability to trigger non-specific single-stranded DNA/RNA cleavage activity after specific target recognition and Cas enzyme activation. This cleavage activity...

article 2022

document

Rapid and reliable discrimination between Shigella species and Escherichia coli using MALDI-TOF mass spectrometry

Paauw, A. (author), Jonker, D. (author), Roeselers, G. (author), Heng, J.M.E. (author), Mars-Groenendijk, R.H. (author), Trip, H. (author), Molhoek, E.M. (author), Jansen, H.J. (author), van der Plas, J. (author), de Jong, A.L. (author), Majchrzykiewicz-Koehorst, J.A. (author), Speksnijder, A.G.C.L. (author)

E. coli-. Shigella species are a cryptic group of bacteria in which the Shigella species are distributed within the phylogenetic tree of E. coli. The nomenclature is historically based and the discrimination of these genera developed as a result of the epidemiological need to identify the cause of shigellosis, a severe disease caused by Shigella...

article 2015

document

OmpU as a biomarker for rapid discrimination between toxigenic and epidemic Vibrio cholerae O1/O139 and non-epidemic Vibrio cholerae in a modified MALDI-TOF MS assay

Paauw, A. (author), Trip, H. (author), Niemcewicz, M. (author), Sellek, R. (author), Heng, J.M.E. (author), Mars-Groenendijk, R.H. (author), de Jong, A.L. (author), Majchrzykiewicz-Koehorst, J.A. (author), Olsen, J.S. (author), Tsivtsivadze, E. (author)

Background Cholera is an acute diarrheal disease caused by Vibrio cholerae. Outbreaks are caused by a genetically homogenous group of strains from serogroup O1 or O139 that are able to produce the cholera toxin. Rapid detection and identification of these epidemic strains is essential for an effective response to cholera outbreaks. Results The...

article 2014

document

Identification of a new biomarker for fast discrimination between epidemic and non-epidemic Vibrio cholerae in a modified MALDI-TOF MS assay

Trip, H. (author), Niemcewicz, M. (author), Sellek, R. (author), Heng, J.M. (author), Mars-Groenendijk, R.H. (author), de Jong, A.L. (author), Majchrzykiewicz, J.A. (author), Olsen, J.S. (author), Tsivtsivadze, E. (author), Paauw, A. (author)

conference paper 2013

document

Inverted analogs of the antibiotic gramicidin S with an improved biological profile

Kapoerchan, V.V. (author), Knijnenburg, A.D. (author), Keizer, P. (author), Spalburg, E. (author), de Neeling, A.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), Otero, J.M. (author), Llamas-Saiz, A.L. (author), van Raaij, M.J. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author)

A series of gramicidin S derivatives 4-15 are presented that have four ornithine residues as polar protonated side chains and two central hydrophobic amino acids with unaltered turn regions. These peptides were screened against human erthrocytes and our standard panel of Gram negative- and Gram positive bacteria, including four MRSA strains....

article 2012

document

Ring-extended gramicidin S analogs Containing cis δ-sugar amino acid turn mimetics with varying ring size

Knijnenburg, A.D. (author), Spalburg, E. (author), de Neeling, A.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), Grotenbreg, G.M. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author)

This article presents a series of ring-extended gramicidin S derivatives, 9-14, that have four ornithine residues as polar protonated side chains and one modified turn region containing a mono-functionalized cis-δ-oxetane, δ-furanoid, or δ-pyranoid sugar amino acid residue. Of the GS analogs evaluated, we identified compound 7, which contains...

article 2012

document

Synthesis and evaluation of strand and turn modified ring-extended gramicidin S derivatives

Knijnenburg, A.D. (author), Kapoerchan, V.V. (author), Grotenbreg, G.M. (author), Spalburg, E. (author), de Neeling, A.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), Otero, J.M. (author), Llamas-Saiz, A.L. (author), van Raaij, M.J. (author), Ravensbergen, B. (author), Nibbering, P.H. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author)

In this paper, we describe the crystal structure of previously reported ring-extended gramicidin S (GS) derivative 2 (GS14K4), containing a d-amino acid residue in one of the β-strand regions. This structure is in agreement with a previously reported modeling study of the same molecule. The polar side chain of the additional d-amino acid residue...

article 2011

document

Exploring the conformational and biological versatility of ß-turn-modified gramicidin s by using sugar amino acid homologues that vary in ring size

Knijnenburg, A.D. (author), Tuin, A.W. (author), Spalburg, E. (author), de Neeling, A.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), Otero, J.M. (author), Llamas-Saiz, A.L. (author), van Raaij, M.J. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author)

Monobenzylated sugar amino acids (SAAs) that differ in ether ring size (containing an oxetane, furanoid, and pyranoid ring) were synthesized and incorporated in one of the ß-turn regions of the cyclo-decapeptide gramicidin S (GS). CD, NMR spectroscopy, modeling, and X-ray diffraction reveal that the ring size of the incorporated SAA moieties...

article 2011

document

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

Kapoerchan, V.V. (author), Spalburg, E. (author), de Neeling, A.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), de Otero, J.M. (author), Ferraces-Casais, P. (author), Llamas-Saiz, A.L. (author), van Raaij, M.J. (author), van Doorn, J. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author)

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...

article 2010

document

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

Kapoerchan, V.V. (author), Knijnenburg, A.D. (author), Niamat, M. (author), Spalburg, E. (author), de Neeling, A.J. (author), Nibbering, P.H. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), Otero, J.M. (author), Llamas-Saiz, A.L. (author), van Raaij, M.J. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author), TNO Defensie en Veiligheid (author)

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...

article 2010

document

Tuning hydrophobicity of highly cationic tetradecameric Gramicidin S analogues using adamantane amino acids

Knijnenburg, A.D. (author), Kapoerchan, V.V. (author), Spalburg, E. (author), de Neeling, A.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author), TNO Defensie en Veiligheid (author)

Ring extended Gramicidin S analogues containing adamantane amino acids and six cationic residues were designed and evaluated. Systematic replacement of the hydrophobic residues with adamantane amino acids resulted in a small set of compounds with varying amphipathic character. It was found that the amphipathicity of these compounds is correlated...

article 2010

document

Chicken cathelicidin-2-derived peptides with enhanced immunomodulatory and antibacterial activities against biological warfare agents

Molhoek, E.M. (author), van Dijk, A. (author), Veldhuizen, E.J.A. (author), Dijk-Knijnenburg, H. (author), Mars-Groenendijk, R.H. (author), Boele, L.C.L. (author), Kaman-van Zanten, W.E. (author), Haagsman, H.P. (author), Bikker, F.J. (author), TNO Defensie en Veiligheid (author)

Host defence peptides (HDPs) are considered to be excellent candidates for the development of novel therapeutic agents. Recently, it was demonstrated that the peptide C1-15, an N-terminal segment of chicken HDP cathelicidin-2, exhibits potent antibacterial activity while lacking cytotoxicity towards eukaryotic cells. In the present study, we...

article 2010

document

Synthesis and biological evaluation of novel gramicidin s analogues

Tuin, A.W. (author), Palachanis, D.K. (author), Buizert, A. (author), Grotenbreg, G.M. (author), Spalburg, E. (author), de Neeling, A.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author), TNO Defensie en Veiligheid (author)

The synthesis of three new analogues of the cyclic cationic antimicrobial peptide Gramicidin S is described. These derivatives contain a modified turn region in which the DPhe-Pro motif has been replaced by a constrained furanoid sugar amino acid or a flexible linear aminoethoxy acetic acid moiety. Structural analysis revealed conformational...

article 2009

document

In vitro toxicity screening of colored smokes (Poster session)

Polhuijs, M. (author), Alblas, M.J. (author), Makkus, J.C. (author), van der Meer, J.A. (author), Mars-Groenendijk, R.H. (author), Groeneveld, F.R. (author), Norbart, M.E.W. (author), Langenberg, J.P. (author), Lingen, J.N.J. (author), TNO Defensie en Veiligheid (author)

conference paper 2009

document

Synthesis and biological evaluation of asymmetric gramicidin S analogues containing modified d-phenylalanine residues

van der Knaap, M. (author), Engels, E. (author), Busscher, H.J. (author), Otero, J.M. (author), Llamas-Saiz, A.L. (author), van Raaij, M.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author), TNO Defensie en Veiligheid (author)

The synthesis of new analogues of the cationic antimicrobial peptide gramicidin S, having a modified d-phenylalanine residue, their antibacterial properties against several Gram positive and negative strains, as well as their hemolytic activity is reported. © 2009 Elsevier Ltd. All rights reserved.

article 2009

document

Ring-extended derivatives of gramicidin S with furanoid sugar amino acids in the turn region have enhanced antimicrobial activity

Knijnenburg, A.D. (author), Spalburg, E. (author), de Neeling, A.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), Grotenbreg, G.M. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author), TNO Defensie en Veiligheid (author)

(Chemical Equation Presented) A series of ring-extended gramicidin S (GS) derivatives containing furanoid sugar amino acids were evaluated. Although the extended GS derivatives have a less well-defined secondary structure as determined by NMR and CD, some derivatives show an improved biological profile, namely, an increased antibacterial...

article 2009

document

In vitro toxicity screening of colored smokes

Langenberg, J.P. (author), Alblas, M.J. (author), Makkus, J.C. (author), van der Meer, J.A. (author), Mars-Groenendijk, R.H. (author), Groeneveld, F.R. (author), Norbert, M. (author), van Lingen, J.N.J. (author), TNO Defensie en Veiligheid (author)

Data on the acute and/or long-term toxicity of colored smokes appear to be scarce and inconsistent. Therefore, the objective of this study is to obtain more insight on this matter. For this purpose, existing platforms for in vitro toxicity screening are evaluated with respect to their applicability to determining the toxicity of colored smokes....

conference paper 2009

document

Structural and biological evaluation of some loloatin C analogues

Tuin, A.W. (author), Grotenbreg, G.M. (author), Spalburg, E. (author), de Neeling, A.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), van der Marel, G.A. (author), Overkleeft, H.S. (author), Overhand, M. (author), TNO Defensie en Veiligheid (author)

Loloatin C is a cyclic cationic antimicrobial peptide which is active against Gram positive as well as certain Gram negative bacteria. Unfortunately, it is equally potent against human erythrocytes. To probe the structure-activity relationship of this promising antibiotic peptide, amino acid substitution and/or incorporation of a constraint...

article 2009

document

Detection of sulfur mustard adducts in human callus by phage antibodies

Bikker, F.J. (author), Mars-Groenendijk, R.H. (author), Noort, D. (author), Fidder, A. (author), van der Schans, G.P. (author), TNO Defensie en Veiligheid (author)

As part of a research program to develop novel methods for diagnosis of sulfur mustard exposure in the human skin the suitability of phage display was explored. Phage display is a relative new method that enables researchers to quickly evaluate a huge range of potentially useful antibodies, thereby bypassing the more costly and time-consuming...

article 2007