Leo J. de Koning

Learn More
The ability of Candida albicans to switch from yeast to hyphal growth is essential for its virulence. The walls and especially the covalently attached wall proteins are involved in the primary host-pathogen interactions. Three hyphal induction methods were compared, based on fetal calf serum, the amino sugar N-acetylglucosamine (GlcNAc) and the mammalian(More)
BACKGROUND This study aimed at exploring the molecular physiological consequences of a major redirection of carbon flow in so-called cyanobacterial cell factories: quantitative whole-cell proteomics analyses were carried out on two (14)N-labelled Synechocystis mutant strains, relative to their (15)N-labelled wild-type counterpart. Each mutant strain(More)
The mucosal layers colonized by the pathogenic fungus Candida albicans differ widely in ambient pH. Because the properties and functions of wall proteins are probably pH dependent, we hypothesized that C. albicans adapts its wall proteome to the external pH. We developed an in vitro system that mimics colonization of mucosal surfaces by growing biomats at(More)
A new method is presented to screen proteolytic mass maps of cross-linked protein complexes for the presence of cross-linked peptides and for the verification of proposed structures. On the basis of the incorporation of 18O from isotopically enriched water into the C-termini of proteolytic peptides, cross-linked peptides are readily distinguished in mass(More)
The opportunistic fungal pathogen Candida albicans has developed various ways to overcome iron restriction in a mammalian host. Using different surface proteins, among them membrane- and wall-localized glycosylphosphatidylinositol (GPI) proteins, it can exploit iron from host haemoglobin, ferritin and transferrin. Culturing C. albicans in rich medium(More)
Mass spectrometric structural analysis of crosslinked peptides is a powerful method to elucidate the spatial arrangement of polypeptides in protein complexes. Our aim is to develop bifunctional crosslinkers that, after crosslinking protein complexes followed by proteolytic digestion, give rise to crosslinked peptides that can be readily tracked down by mass(More)
Fluconazole is a commonly used antifungal drug that inhibits Erg11, a protein responsible for 14α-demethylation during ergosterol synthesis. Consequently, ergosterol is depleted from cellular membranes and replaced by toxic 14α-methylated sterols, which causes increased membrane fluidity and drug permeability. Surface-grown and planktonic cultures of(More)
Qualitative phenotypic changes are the integrated result of quantitative changes at multiple regulatory levels. To explain the temperature-induced increase of glycolytic flux in fermenting cultures of Saccharomyces cerevisiae, we quantified the contributions of changes in activity at many regulatory levels. We previously showed that a similar temperature(More)
The molecular structures determine the physical properties of milk proteins and are important for the texture of many dairy-based foods. Bovine alpha-lactalbumin (alpha-LA) is a globular 123 amino acid Ca(2+) binding milk protein. Modification with microbial Ca(2+) independent transglutaminase (MTGase) was used to modify lysines and glutamines in holo and(More)
A versatile software tool, VIRTUALMSLAB, is presented that can perform advanced complex virtual proteomic experiments with mass spectrometric analyses to assist in the characterization of proteins. The virtual experimental results allow rapid, flexible and convenient exploration of sample preparation strategies and are used to generate MS reference(More)