Neurobiochemistry / Ion Channels

Research Overview:

The work of the Neurobiochemistry research laboratory focuses on the determination of the elementary mechanisms that underlie biochemical and biomedical processes. From a detailed understanding of these basic steps, disease and malfunction can be understood and new therapies developed. Proteins targeted in the group are ion channels. For their studies a number of techniques are combined. Basic molecular biology, including PCR-based mutagenesis, cloning, plasmid handling, bacterial and eukaryotic expression of proteins are key techniques to generate defined mutant proteins. Techniques of protein biochemistry include gel electrophoresis, Western Blotting, surface membrane expression, and enzyme kinetics. Ion channel function is assessed using patch-clamp electrophysiology techniques in combination with rapid chemical kinetic methods. Both, recombinant ion channels and channels from primary culture of neurons can be studied in the laboratory. Pharmacological approaches include the determination of mechanisms of receptor inhibition, as well as the study of synergistic effects in drug combinations. These in vitro methods are complemented by cellular toxicity assays and experiments using mouse and zebrafish models for in vitro characterization of drugs and drug combination. A new project on the molecular virology of hepatitis C focuses on the characterization of the hepatitis C p7 ion channel protein as a pharmacological target, the development of functional 7 tests, and the development of novel p7 inhibitors as antiviral drugs. A research initiative of the generation of novel pharmaceuticals from marine sources and medicinal plants has been established with the aim to identify new therapeutic compounds from natural resources in Egypt. The Research Laboratory of Basic Biochemistry is equipped for basic Molecular Biology and Protein Biochemistry. PCR-based site-directed mutagenesis, plasmid preparation, purification and amplification through bacterial expression is established. Protein biochemistry includes eukaryotic expression, protein isolation and purification, analysis of membrane proteins, surface expression analysis, SDS-PAGE and Western Blot, Dot Blot, enzyme kinetics.
For advanced characterisation of ion channel receptors, a patch-clamp setup (incl. Sutter pipette puller, Zeiss Axiovert 400 Fluorescent microscope, HEKA EPC-10 amplifier, Octaflow perfusion system) is established. Culture of eukaryotic clonal cells and primary cells is established in the laboratory.  

Research Topics:

1)Neurobiochemistry:

1.1) Inhibitory glycine receptor
1.2) Ligand-gated ion channels – structure-function relationships and modulation
1.3) Neuroregeneration / neuronal stem cell signaling

2) Marine Biotechnology/Biochemistry – Pharmacology: 

2.1) New agents/pharmaceuticals from marine sources:

Organisms (plants, sponges, mollusks, echinoderms) from the Red Sea are collected and crude extracts prepared by standard methods (methanolic, acetone, organic solvents, …). Crude extracts are tested in vitro (patch-clamp) for activity on glycine, acetylcholine, Glutamate and GABA receptors. Further tests include cytotoxicity and cytoprotection, neuroregeneration, antibacterial assays. Based on in vitro results, in vivo tests (artemia, mouse, zebrafish) will be performed.
The initiative has been highly successful in identifying novel sources for pharmaceuticals.

3) Virology – p7 channels in hepatitis C:

Principle:

The p7 protein is an integral component of the hepatitis C virus. Here, we will generate a plasmid construct for recombinant expression of the p7 proteins in HEK cells. Various p7 variants, with genotype-specific sequences will be generated and tested for surface expression and channel activity. New channel blockers will be tested and their inhibitory potency compared to amantadine and rimantadine. Finally, we will try to establish an in vivo test system for promising drug candidates as new hepatitis C treatment.

Techniques:

Animal handling, animal disease models, protein biochemistry, SDS-PAGE, Western Blot, Bioassays of pharmaceuticals.