Tony Christopeit

• PhD
• Researcher at Roche, Penzberg, Germany

Monoclonal antibody (mAb) pharmaceuticals consist of a plethora of different proteoforms with different functional characteristics, including pharmacokinetics and pharmacodynamics, requiring their individual assessment. Current binding techniques do not distinguish between coexisting proteoforms requiring tedious production of enriched proteoforms....

Removal of apoptotic cells by phagocytes (also called efferocytosis) is a crucial process for tissue homeostasis. Professional phagocytes express a plethora of surface receptors enabling them to sense and engulf apoptotic cells, thus avoiding persistence of dead cells and cellular debris and their consequent effects. Dysregulation of efferocytosis...

Metallo-β-lactamases (MBLs) are an emerging cause of bacterial antibiotic resistance by hydrolysing all classes of β-lactams except monobactams, and the MBLs are not inhibited by clinically available serine-β-lactamase inhibitors. Two of the most commonly encountered MBLs in clinical isolates worldwide - the New Delhi metallo-β-lactamase (NDM-1) an...

Many class D β‐lactamases form dimers in solution. The functional basis of the dimerization of OXA‐48‐like class D β‐lactamases is not known, but in order to understand the structural requirements for dimerization of OXA‐48 we have characterized the dimer interface. Size‐exclusion chromatography, small angle X‐ray scattering and nuclear magnetic r...

Enzymatic depolymerization of recalcitrant polysaccharides plays a key role in accessing the renewable energy stored within lignocellulosic biomass, and natural biodiversities may be explored to discover microbial enzymes that have evolved to conquer this task in various environments. Here, a metagenome from a thermophilic microbial community was m...

β-Lactam antibiotics are of utmost importance when treating bacterial infections in the medical community. However, currently their utility is threatened by the emergence and spread of β-lactam resistance. The most prevalent resistance mechanism to β-lactam antibiotics is expression of β-lactamase enzymes. One way to overcome resistance caused by β...

Metallo-β-lactamases (MBLs) threatens the effectiveness of β-lactam antibiotics including carbapenems, and is a concern for the global public health. β-lactam/β-lactamase inhibitor combinations active against class A and class D carbapenemases are used, but currently no clinically useful MBL inhibitor is available. Tripoli metallo-β-lactamase-1 (TM...

The increasing number of pathogens expressing metallo-β-lactamases (MBLs), and in this way achieving resistance to β-lactam antibiotics, is a significant threat to global public health. A promising strategy to treat such resistant pathogens is the co-administration of MBL inhibitors together with β-lactam antibiotics. However, an MBL inhibitor suit...

The spread of antibiotic resistant bacteria is a global threat that shakes the foundations of modern healthcare. β-Lactamases are enzymes that confer resistance to β-lactam antibiotics in bacteria and there is a critical need for new inhibitors of these enzymes for combination therapy together with an antibiotic. With this in mind, we have screened...

The inhibition of metallo-β-lactamases (MBL) can prevent the hydrolysis of β-lactam antibiotics and hence is a promising strategy for the treatment of antibiotic resistant infections. In this study, we present a novel reversible covalent inhibitor of the clinically relevant MBL New Delhi metallo-β-lactamase 1 (NDM-1). Electrospray ionization-mass s...

Metallo-β-lactamases (MBLs) render bacteria resistant to β-lactam antibiotics and are interesting drug targets to prevent the hydrolysis of β-lactam antibiotics. So far, there are no MBL inhibitors in clinical use and particularly the design of broad spectrum inhibitors targeting several MBLs has been difficult. In this study, we report four fragme...

Metallo-β-lactamase (MBL) inhibitors can restore the function of carbapenem antibiotics and therefore help to treat infections of antibiotic resistant bacteria. In this study, we report novel fragments inhibiting the clinically relevant MBL VIM-2. The fragments were identified from a library of 490 fragments using an orthogonal screening approach b...

The screening of extracts from marine organisms is a widely used strategy to discover new drug leads. A common problem in the screening process is the generation of false positive hits through unspecific effects from the complex chemical composition of the crude extracts. In this study, we explored a combination of a fluorescence resonance energy t...

A surface plasmon resonance biosensor assay was established for studying the interactions of 51 histaminergic and 15 GABAergic ligands with homo-oligomeric β3 GABA(A) receptors. Detergent solubilized receptors were successfully immobilized via affinity-capture on biosensor surfaces. The interaction kinetics of both histaminergic and GABAergic ligan...

A surface plasmon resonance (SPR) biosensor-based assay for membrane-embedded full-length BACE1 (β-site amyloid precursor protein cleaving enzyme 1), a drug target for Alzheimer's disease, has been developed. It allows the analysis of interactions with the protein in its natural lipid membrane environment. The enzyme was captured via an antibody re...

High-affinity binders for the C-reactive protein (CRP), with dissociation constants in the pM to nM range and selectivities in human serum comparable to those of antibodies, were obtained by conjugation of 16 designed polypeptides to phosphocholine, a small molecule that binds CRP with a KDvalue of 5I . The polypeptides were not designed specifical...

The interactions between Ca2+ and C-reactive protein (CRP) have been characterized using a surface plasmon resonance (SPR) biosensor. The protein was immobilized on a sensor chip, and increasing concentrations of Ca2+ or phosphocholine were injected. Binding of Ca2+ induced a 10-fold higher signal than expected from the molecular weight of Ca2+. It...

Increasing evidence indicates that polypeptide aggregation often involves a nucleation and a growth phase, although the relationship between the factors that determine these two phases has not yet been fully clarified. We present here an analysis of several mutations at different sites of the Abeta(1-40) peptide, including those associated with ear...

Amyloid formation is a nucleation-dependent process that is accelerated dramatically in vivo and in vitro upon addition of appropriate fibril seeds. A potent species barrier can be effective in this reaction if donor and recipient come from different biological species. This species barrier is thought to reflect differences in the amino acid sequen...

We have determined the critical concentrations of a set of 18 variants of Alzheimer's Abeta(1-40) peptide, each carrying a different residue at position 18. We find that the critical concentrations depend on the hydrophobicity and beta-sheet propensity of residue 18, and therefore on properties that we identified previously to affect also the kinet...

The formation of polypeptide aggregates represents a nucleated polymerization reaction in which an initial nucleation event (lag phase) is followed by the extension of newly formed nuclei into larger aggregates, including fibrils (growth phase). The efficiencies of these reactions relate to the lag time (lag phase) and to the rate of aggregation (g...

We report here a recombinant expression system that allows production of large quantities of Alzheimer's Abeta(1-40) peptide. The material is competent to dissolve in water solutions with "random-coil properties," although its conformation and factual oligomerization state are determined by the physico-chemical solution conditions. When dissolved i...