Bactericidal oncocin derivatives with superior serum stabilities

Knappe, Daniel; Kabankov, Natalja; Hoffmann, Ralf

doi:10.1016/j.ijantimicag.2010.10.028

Cited by 46 publications

(52 citation statements)

References 13 publications

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“…Concentrated human erythrocytes were washed, suspended in PBS (2% [vol/vol]; 50 l), added to a serial peptide dilution series from 600 to 5 g/ml in PBS (50 l; 96-well polypropylene plates, V bottom; Greiner Bio-One GmbH), and incubated (37°C, 1 h) (23). After centrifugation (1,000 ϫ g), the absorbance of the supernatants was determined in a 384-well plate (flat bottom; Greiner Bio-One GmbH) at 405 nm in a Paradigm microplate reader.…”

Section: Methodsmentioning

confidence: 99%

“…Peptides (15 g) were dissolved either in 25% (vol/ vol) aqueous or undiluted pooled mouse serum (100 l; PAA Laboratories GmbH) and incubated at 37°C (23). Aliquots were taken in duplicate or triplicate after 0, 30, 60, 120, 240, and 360 min and precipitated by addition of trichloroacetic acid to a final concentration of 3% (wt/vol).…”

Section: Flow Cytometry (Facs)mentioning

confidence: 99%

“…The Hyp substitutions did not affect the serum stability (data not shown). Thus, we did not further investigate the Hyp analogs, although they might increase the stability against bacterial proteases (23) or improve the pharmacokinetics.…”

Section: Fig 1 Degradation Of Api88 In 25% Aqueous Mouse Serum (Top) mentioning

confidence: 99%

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Novel Apidaecin 1b Analogs with Superior Serum Stabilities for Treatment of Infections by Gram-Negative Pathogens

Berthold

Czihal

Fritsche

et al. 2013

Antimicrob Agents Chemother

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dProline-rich antimicrobial peptides (PrAMPs) from insects and mammals have recently been evaluated for their pharmaceutical potential in treating systemic bacterial infections. Besides the native peptides, several shortened, modified, or even artificial sequences were highly effective in different murine infection models. Most recently, we showed that the 18-residue-long peptide Api88, an optimized version of apidaecin 1b, was efficient in two different animal infection models using the pathogenic Escherichia coli strains ATCC 25922 and Neumann, with a promising safety margin. Here, we show that Api88 is degraded relatively fast upon incubation with mouse serum, by cleavage of the C-terminal leucine residue. To improve its in vitro characteristics, we aimed to improve its serum stability. Replacing the C-terminal amide by the free acid or substituting Arg-17 with Lornithine or L-homoarginine increased the serum stabilities by more than 20-fold (half-life, ϳ4 to 6 h). These analogs were nontoxic to human embryonic kidney (HEK 293), human hepatoma (HepG2), SH-SY5Y, and HeLa cells and nonhemolytic to human erythrocytes. The binding constants of all three analogs with the chaperone DnaK, which is proposed as the bacterial target of PrAMPs, were very similar to that of Api88. Of all the analogs tested, Api137 (Gu-ONNRPVYIPRPRPPHPRL; Gu is N,N,N=,N=-tetramethylguanidino) appeared most promising due to its high antibacterial activity, which was very similar to Api88. Positional alanine and D-amino acid scans of Api137 indicated that substitutions of residues 1 to 13 had only minor effects on the activity against an E. coli strain, whereas substitutions of residues 14 to 18 decreased the activity dramatically. Based on the significantly improved resistance to proteolysis, Api137 appears to be a very promising lead compound that should be even more efficient in vivo than Api88.

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Section: Methodsmentioning

confidence: 99%

Section: Flow Cytometry (Facs)mentioning

confidence: 99%

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Novel Apidaecin 1b Analogs with Superior Serum Stabilities for Treatment of Infections by Gram-Negative Pathogens

Berthold

Czihal

Fritsche

et al. 2013

Antimicrob Agents Chemother

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“…The higher in vivo efficacy of Onc112 can be explained by its activity, which was 2-fold (MIC ¼ 2 mg/L) that of Onc72. 10 As Onc72 and Onc112 are the first representatives of this antibiotic class investigated in vivo, we studied their pharmacokinetics to evaluate their in vivo distribution. Thus, we developed a sensitive strategy for targeted quantification of both peptides and the two possible metabolites 1-11 and 1-14 by combining solid-phase extraction, reversed-phase chromatography and multiple reaction monitoring (MRM) on an ESI-QqLIT-MS. 12 For method development and validation, see the Supplementary data (Additional Results, Tables S6 to S8 and Figures S1 to S5).…”

Section: Infection Modelmentioning

confidence: 99%

“…5 Oncocin analogues Onc72 (VDKPPYLPRPRPPROIYNO-NH 2 , O¼ ornithine) and Onc112 (VDKPPYLPRPRPPRrIYNr-NH 2 , r¼D-arginine) are highly active against Gram-negative bacteria including Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii, which are currently under surveillance by the ECDC. 2 Their MICs range from 2 to 8 mg/L, 10 and their serum half-lives exceed 3 h. Importantly, Onc72 has been highly efficient in two lethal murine infection models to treat E. coli and multiresistant KPC-producing K. pneumoniae bacteraemia with an effective dose (ED 50 ) of 2 mg/kg. It is also well tolerated when multiply injected intraperitoneally at doses of 40 mg/kg body weight.…”

Section: Introductionmentioning

confidence: 99%

Pharmacokinetics andin vivoefficacy of optimized oncocin derivatives

Schmidt

Ostorházi

Wende

et al. 2016

J. Antimicrob. Chemother.

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Objectives: To evaluate the efficacy of antimicrobial peptide Onc112 in a lethal Escherichia coli infection model and the pharmacokinetics of Onc72 and Onc112 administered intravenously or intraperitoneally in mice.Methods: Onc72, Onc112 and their major metabolites in blood, kidneys, liver, brain and urine were quantified by MS using multiple reaction monitoring (MRM) and isotope-labelled peptides.Results: Onc112 rescued all animals when administered intraperitoneally at a dose of 2.5 mg/kg and was thus slightly more efficient than Onc72. The MRM method provided limits of quantification in plasma, urine and kidney, liver and brain homogenates of 7 -80 mg/L, well below the MICs of 2 -4 mg/L. Onc72 and Onc112 reached all organs within 10 min when administered intraperitoneally (5 mg/kg). Their initial concentrations in plasma were 11.9 and 22.6 mg/L, respectively, with elimination t 1/2 values of 14 and 21 min. The peptide concentrations in blood remained above their MICs for 20 min for Onc72 and 80 min for Onc112. The highest peptide concentrations were detected in kidney homogenates, which also contained the highest content of metabolites, indicating, together with the results from analysis of urine samples, that both peptides are cleared through the kidneys.Conclusions: Onc72 and Onc112 reach organs, including the brain, within 10 min after intravenous and intraperitoneal administration. Onc112 remained in blood at concentrations above its MIC for 80 min. The pharmacokinetic profiles explain the high in vivo efficacies in models of systemic infection and indicate the potential use of these agents for the treatment of urinary tract infections.

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