PRDM9 forms a trimer by interactions within the zinc finger array.

PRDM9 is a trans-acting factor directing meiotic recombination to specific DNA-binding sites by its zinc finger (ZnF) array. It was suggested that PRDM9 is a multimer; however, we do not know the stoichiometry or the components inducing PRDM9 multimerization. In this work, we used binding studies and characterized with electrophoretic mobility shift assays, mass spectrometry, and fluorescence correlation spectroscopy the stoichiometry of the PRDM9 multimer of two different murine PRDM9 alleles carrying different tags and domains produced with different expression systems.

Proteomic analysis of human-derived cell culture supplements.

Objective: Development of cell therapy and advanced therapy medicinal products depends on in vitro expansion of human cells in fetal bovine serum (FBS) supplemented media. Human-derived supplements, such as human serum (huS) and human platelet lysate (hPL), represent suitable alternatives to FBS. Various studies demonstrated that the use of these human alternatives result in comparable or even improved proliferation and expansion ratios.

A comparison of nano-electrospray gas-phase electrophoretic mobility macromolecular analysis and matrix-assisted laser desorption/ionization linear time-of-flight mass spectrometry for the characterization of the recombinant coagulation glycoprotein von Willebrand factor.

Von Willebrand factor (VWF), an adhesive glycoprotein with an approximate molecular weight (MW) of the monomer of 260 kDa, circulates in human blood plasma as a series of multimers ranging in size up to 20.000 kDa; thus the determination of the accurate MW of the monomer is of great importance and due to its high MW quite challenging. In this study accurate MW determination of intact recombinant VWF monomer (rVWF) was performed with GEMMA (gas-phase electrophoretic mobility macromolecular analysis) and MALDI TOF MS (matrix-assisted laser desorption/ionization linear time-of-flight mass spectrometry).

GEMMA and MALDI-TOF MS of reactive PEGs for pharmaceutical applications.

One of the most prominent polymer group applied for drug conjugation is poly(ethylene) glycol (PEG). Since drug production is subjected to strict restrictions on the part of the FDA and EMEA, also PEG has to be characterized accurately. Particularly its molecular mass distribution (MMD) and polydispersity can result in unrequested inhomogeneous final products.

Development of a MALDI two-layer volume sample preparation technique for analysis of colored conidia spores of Fusarium by MALDI linear TOF mass spectrometry.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been proved to be a powerful tool for the identification and characterization of microorganisms based on their surface peptide/protein pattern. Because of the complexity of microorganisms, there are no standardized protocols to acquire reproducible peptide/protein profiles for a broad range of microorganisms and for fungi in particular. Small variations during MALDI MS sample preparation affect the quality of mass spectra quite often.

Evaluation of matrix-assisted laser desorption/ionization (MALDI) preparation techniques for surface characterization of intact Fusarium spores by MALDI linear time-of-flight mass spectrometry.

Unambiguous identification of mycotoxin-producing fungal species as Fusarium is of great relevance to agriculture and the food-producing industry as well as in medicine. Protein profiles of intact fungal spores, such as Penicillium, Aspergillus and Trichoderma, derived from matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were shown to provide a rapid and straightforward method for species identification and characterization. In this study, we applied this approach to five different Fusarium spp.

Comparing standard and microwave assisted staining protocols for SDS-PAGE of glycoproteins followed by subsequent PMF with MALDI MS.

The detection of glycoproteins on SDS-PAGE gels is a very challenging task as glycan moieties can inhibit the protein-dye interaction or protein-silver reaction slowing down or even completely preventing the staining process. Additionally the applied staining procedure can influence the total number of detected peptides after in-gel digestion. Three in SDS-PAGE commonly used staining procedures (silver nitrate, CBB R250 and colloidal CBB G250) were evaluated in terms of duration, sensitivity and obtainable sequence coverage after PMF.