Studies on the X-Ray and Solution Structure of FeoB from Escherichia coli BL21.

The ferrous iron transporter FeoB is an important factor in the iron metabolism of many bacteria. Although several structural studies have been performed on its cytosolic GTPase domain (NFeoB), the full-length structure of FeoB remains elusive. Based on a crystal packing analysis that was performed on crystals of NFeoB, a trimeric structure of the FeoB channel was proposed, where the transport pore runs along the trimer axis.

Expression, purification and spin labelling of the ferrous iron transporter FeoB from Escherichia coli BL21 for EPR studies.

The ferrous iron transporter FeoB is an important factor in the iron metabolism of various bacteria. As a membrane bound GTPase it also represents an interesting evolutionary link between prokaryotic and eukaryotic membrane signalling pathways. To date, structural information for FeoB is limited to the cytosolic GTPase domain and structural features such as the oligomeric state of the transporter in the membrane, and thereby the nature of the transport pore are a matter of constant debate.

Spectroscopic studies on peptides and proteins with cysteine-containing heme regulatory motifs (HRM).

The role of heme as a cofactor in enzymatic reactions has been studied for a long time and in great detail. Recently it was discovered that heme can also serve as a signalling molecule in cells but so far only few examples of this regulation have been studied. In order to discover new potentially heme-regulated proteins, we screened protein sequence databases for bacterial proteins that contain sequence features like a Cysteine-Proline (CP) motif, which is known for its heme-binding propensity.

EPR-based approach for the localization of paramagnetic metal ions in biomolecules.

Metal ions play an important role in the catalysis and folding of proteins and oligonucleotides. Their localization within the three-dimensional fold of such biomolecules is therefore an important goal in understanding structure-function relationships. A trilateration approach for the localization of metal ions by means of long-range distance measurements based on electron paramagnetic resonance (EPR) is introduced.

High-resolution crystal structure of spin labelled (T21R1) azurin from Pseudomonas aeruginosa: a challenging structural benchmark for in silico spin labelling algorithms.

Background: EPR-based distance measurements between spin labels in proteins have become a valuable tool in structural biology. The direct translation of the experimental distances into structural information is however often impaired by the intrinsic flexibility of the spin labelled side chains. Different algorithms exist that predict the approximate conformation of the spin label either by using pre-computed rotamer libraries of the labelled side chain (rotamer approach) or by simply determining its accessible volume (accessible volume approach).

1-alkyl-8-(piperazine-1-sulfonyl)phenylxanthines: development and characterization of adenosine A2B receptor antagonists and a new radioligand with subnanomolar affinity and subtype specificity.

A new series of 1-alkyl-8-(piperazine-1-sulfonyl)phenylxanthines was designed, synthesized, and characterized in radioligand binding and functional assays at A(2B) adenosine receptors. A(2B) antagonists with subnanomolar affinity and high selectivity were discovered. The most potent compounds were 1-ethyl-8-(4-(4-(4-trifluoromethylbenzyl)piperazine-1-sulfonyl)phenyl)xanthine (24, PSB-09120, K(i) (human A(2B)) = 0.