Impurity determination for hepcidin by liquid chromatography-high resolution and ion mobility mass spectrometry for the value assignment of candidate primary calibrators.

In metrology institutes, the state-of-the-art for purity analysis of peptides/proteins mainly addresses short and unfolded peptides. Important developments are anticipated for the characterization of nonlinear peptides or proteins. Hepcidin 1-25 is an interesting model system because this small protein contains four disulfide bridges with a particular connectivity that is difficult to reproduce and could induce a bias in quantification.

The peptaibiotics database--a comprehensive online resource.

In this work, we present the 'Peptaibiotics Database' (PDB), a comprehensive online resource, which intends to cover all Aib-containing non-ribosomal fungal peptides currently described in scientific literature. This database shall extend and update the recently published 'Comprehensive Peptaibiotics Database' and currently consists of 1,297 peptaibiotic sequences. In a literature survey, a total of 235 peptaibiotic sequences published between January 2013 and June 2014 have been compiled, and added to the list of 1,062 peptides in the recently published 'Comprehensive Peptaibiotics Database'.

The comprehensive peptaibiotics database.

Peptaibiotics are nonribosomally biosynthesized peptides, which - according to definition - contain the marker amino acid α-aminoisobutyric acid (Aib) and possess antibiotic properties. Being known since 1958, a constantly increasing number of peptaibiotics have been described and investigated with a particular emphasis on hypocrealean fungi. Starting from the existing online 'Peptaibol Database', first published in 1997, an exhaustive literature survey of all known peptaibiotics was carried out and resulted in a list of 1043 peptaibiotics.

Heterochromatin influences the secondary metabolite profile in the plant pathogen Fusarium graminearum.

Chromatin modifications and heterochromatic marks have been shown to be involved in the regulation of secondary metabolism gene clusters in the fungal model system Aspergillus nidulans. We examine here the role of HEP1, the heterochromatin protein homolog of Fusarium graminearum, for the production of secondary metabolites. Deletion of Hep1 in a PH-1 background strongly influences expression of genes required for the production of aurofusarin and the main tricothecene metabolite DON.

Marker peptide selection for the determination of hazelnut by LC-MS/MS and occurrence in other nuts.

The aim of this work was identifying and selecting hazelnut marker peptides and subsequently developing a complementary method of common immunoassay for the detection of hazelnut. For this purpose, at first, an in silico digestion of three major hazelnut allergens (Cor a 8, Cor a 9 and Cor a 11) was performed to get information about expected peptides. After extraction and trypsin digestion of hazelnut proteins, the samples were measured with tandem mass spectrometry (MS/MS) by direct infusion, which led to identification of 14 peptides.

Selection of possible marker peptides for the detection of major ruminant milk proteins in food by liquid chromatography-tandem mass spectrometry.

The aim of this work was the determination of peptides, which can function as markers for identification of milk allergens in food samples. Emphasis was placed on two casein proteins (α- and β-casein) and two whey proteins (α-lactalbumin and β-lactoglobulin). In silico tryptic digestion provided preliminary information about the expected peptides.

Identification and profiling of volatile metabolites of the biocontrol fungus Trichoderma atroviride by HS-SPME-GC-MS.

In the present study we describe a method, which is based on solid phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS) and which can be used for the profiling of microbial volatile organic compounds (MVOCs) in the headspace (HS) of cultures of filamentous fungi. The method comprises the following successive steps: 1. growth of the fungus on a solid culture medium directly in headspace vials, 2.

Characterisation of the peptaibiome of the biocontrol fungus Trichoderma atroviride by liquid chromatography/tandem mass spectrometry.

The present study describes the liquid chromatography/tandem mass spectrometry (LC/MS/MS)-based screening and characterisation of linear antibiotic alpha-aminoisobutyric acid (Aib)-containing non-ribosomal peptides (NRP) in culture samples of the filamentous fungus Trichoderma atroviride ATCC 74058. Fungal culture filtrates were enriched by solid-phase extraction (SPE) and separated by reversed-phase high-performance liquid chromatography (HPLC), prior to mass spectrometric (MS) and tandem mass spectrometric (MS/MS) analysis on a triple quadrupole-linear ion trap tandem mass spectrometer. A workflow consisting of two alternative screening strategies was applied to search for NRP.

Profiling of trichorzianines in culture samples of Trichoderma atroviride by liquid chromatography/tandem mass spectrometry.

Peptaibols are bioactive linear peptides of 5-20 amino acid residues and contain specific non-proteinogenic amino acids such as alpha-aminoisobutyric acid (Aib). They are antibiotic secondary metabolites of moulds belonging predominantly to the genus Trichoderma, some species of which are successfully used as biocontrol organisms to fight against plant diseases. In the present study we developed a profiling method for the relative quantification of 16 trichorzianine peptaibols in culture samples of T.

Signaling via the Trichoderma atroviride mitogen-activated protein kinase Tmk 1 differentially affects mycoparasitism and plant protection.

Trichoderma atroviride is a mycoparasite of a number of plant pathogenic fungi thereby employing morphological changes and secretion of cell wall degrading enzymes and antibiotics. The function of the tmk 1 gene encoding a mitogen-activated protein kinase (MAPK) during fungal growth, mycoparasitic interaction, and biocontrol was examined in T. atroviride.