Fakultät für Chemie - Former
Uni von A-Z
Bielefeld University > Department of Chemistry > Organic Chemistry III > Team > Former

Personal data for Janina Lenger

  Janina Lenger
Janina Lenger
PhD student
Room: F2-231
Phone: 0521 106 2145

Activity-based Proteomics

In the first project of my thesis, I am investigating matrix metalloproteases (At-MMPs) from Arabidopsis thaliana. At-MMPs are a group of five enzymes displaying a high homology to human MMP-7. To elucidate their localization and physiological role, which is still unknown, I am currently working on the transient expression of all five At-MMPs in Nicotiana benthamiana. For isolation and functional characterization, I synthesized probes (e.g. 1) which utilize the broad-spectrum MMP-inhibitor Marimastat as binding partner.

These probes were tested for their inhibitory action on commercially available human MMP-2 and -9 with FRET-pseudo substrates and in surface plasmon resonance binding studies. Preliminary tests prove the concept of extracting active MMPs from complex physiological mixtures using human MMP-2 spiked into Arabidopsis th. extracts with Marimastat-coated beads. 2D-PAGE and tryptic digest followed by MALDI-ToF fingerprint analysis as well as LC-MS/MS are used for protein separation and identification.

The second project of my thesis aims at the selective detection and isolation of sulfatases in and from complex mixtures. Probe-assembly is intended to be orthogonal and modular to ensure an easy exchange of the two building blocks inhibitor and reporter group. The inhibitor moiety is composed of a quinone methide based suicide inhibitor, while biotin or BODIPY serve as reporter groups for pull-down or visualization. The inhibitory activity of the probe relies on covalent bond formation between probe and sulfatase upon cleavage of the sulfate ester by the enzyme. Subsequent fluoride elimination generates a quinone methide intermediate which features an electrophilic position. Any nucleophile in the sulfatase active site is able to attack this carbon atom.

Preliminary tests of this tailored inhibitor conjugate show a selective inhibition among the sulfatases tested so far, which can be followed in real-time by19 F-NMR-spectroscopy.

Diploma thesis: "Synthese und Anwendung einer Sonde für Matrix-Metalloproteasen in der funktionellen Proteomik"

Molecular tools for metalloprotease subproteome generation, M. Collet, J. Lenger, K. Jenssen, H. P. Plattner, N. Sewald, J. Biotechnol., 129 (2007) 316-328.