Ahmadian Group

Group leader

Title	Name	First Name	Position
PD Dr.	Ahmadian	Reza	Group leader

 For more information on the principal investigator click here...

Researchers

Title	Name	First Name	Position
Dr.	Dvorsky	Radovan	Senior scientist

BioStruct Fellow

Title	Name	First Name	Position
MSc	Dubey	Badri Nath	PhD student

 For more information on the biostruct fellow click here...

Further Team Members

Technicians:	1
Master/Diploma students:	2
PHD/MD students:	8

Contact

AG Ahmadian
Institute of Biochemistry and Molecular Biology II
Heinrich Heine University Düsseldorf
Universitätsstr. 1, Building 22.03.3
40225 Düsseldorf

+49(0)211-81-12384
+49(0)211-81-12726


website:
http://www.uniklinik-duesseldorf.de/biochemieundmolekularbiologiezwei

Expertise in Structural Biology

• Fluorescence Spectroscopy

  Over the past 20 years, substantive technological and methodological developments in fluorescence based applications have ensured that fluorescence spectroscopy is now widely utilized in life sciences. Fluorescence spectroscopy is well established and represents one of the most sensitive and powerful analytical techniques. The use of fluorescence-based spectroscopic methods allows real-time monitoring of bimolecular interactions, including ligand-, DNA- and protein-protein interactions at submicromolar concentrations.
  

• X-ray crystallography
  X-ray crystallography is a powerful technique in studying the three-dimensional structure of macromolecules such as DNA, RNA, proteins. The state-of-art macromolecular crystallography has given us new eyes to look at biology and contributes remarkably to our understanding of the miracle of life. Moreover, one can experimentally determine the structure of a drug target and use the structural information to guide synthesis of compounds based on size, shape and chemical and physical properties.

• Computational biology
  Computational biology combines the knowledge from different disciplines to provide comprehensive view of processes in cells, tissues and organisms. Exploding number of information about the state of proteins in different tissues and their mutual interactions set the platform for a new branch of system biology. With its tools we are beginning to understand extremely complex processes like metabolic and signalling pathways, immunological responses or hormone regulation.

Figure legend: An Electrostatic Steering Mechanism of Cdc42 Recognition by Wiskott-Aldrich Syndrome Proteins. (A) Association of TC10·mantGppNHp with increasing WASp. (B) Kinetics of Cdc42 and TC10 association with the GBD of the WAS proteins. (C) Kinetics of WASp dissociating from mantGppNHp-bound Cdc42 and TC10 in the presence of non-labeled GppNHp-bound GTPases. (D) Cdc42·Gpp(CH2)p·WASpGBD Complex according to Abdul-Manan et al., 1999. Cdc42 is gray and WASpGBD is green. The positions of the critical electrostatics (glutamates of Cdc42 and the lysines of WASpGBD) are depicted in red and blue, respectively. (E) TC10·GppNHp·WASpGBD Complex was modelled on the basis of the TC10·GppNHp structure. The orientation of the structure and the illustration is according to (D). Lys63 and Thr192 of TC10 are shown in blue and cyan. (E) Electrostatic potentials of wildtype and mutant forms of Cdc42 and TC10 are represented by their isosurfaces at –0.1 kbT/ec (red) or +0.1 kbT/ec (blue), respectively. The orientation of the molecules is the same as in (D) and (E) (left panels). Residues critical for the association with WAS proteins, Glu49 (Lys63 in TC10) and Glu178 (Thr192 in TC10) of Cdc42, are indicated for orientation. Note that Glu178 and Thr192 are in fact on the other side of proteins.

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Main areas of research interest

• Control mechanisms of small GTPases
• Structure, Regulation and function of tumor-relevant regulators of small GTPases
• Biomolecular Network Reconstruction of the Rho GTPase signalling at the membrane
• α-helical peptidomimetics in protein-protein interaction

Facilities

The laboratories cover the following gene technology security levels:	S1
The laboratories cover the following biohazard levels:	BSL1

Laboratory Equipment

General equipment available in the laboratories:

• Biochemistry
• Biophysics
• Cell culture
• Molecular biology
• Biotechnology
• Immunology
• Cell Biology
• Microbiology
• Biocomputing
• Imaging

Special equipment, which is not generally available in most laboratories:

• MicroCAl VP-isothermal titration calorimeter (VP-ITC)
• Hi-Tech SF-61 DX2 Stopped-flow instrument
• Perkin-Elmer LS50B Fluorescence spectrometer
• Carl Zeiss LSM 510 Meta confocal microscope

Important References

• Hemsath, L., Dvorsky, R., Fiegen, D., Carlier, M.F. & Ahmadian, M.R. (2005). An Electrostatic Steering Mechanism of Cdc42 Recognition by Wiskott-Aldrich Syndrome Proteins. Mol Cell 20, 313-324
• Dvorsky, R., Blumenstein, L., Vetter, I.R. & Ahmadian, M.R. (2004). Structural insights into the interaction of ROCKI with the switch regions of RhoA. J. Biol. Chem. 279, 7098-7104
• Jaiswal, M., Gremer, L., Dvorsky, R., Haeusler, L.C., Cirstea, I.C., Uhlenbrock, K., Ahmadian, M.R. (2011). Mechanistic insights into specificity, activity and regulatory elements of the RGS-containing Rho-specific guanine nucleotide exchange factors p115, PDZ-RhoGEF (PRG) and Leukemia- associated RhoGEF (LARG). J. Biol. Chem. 286, 18202-18212
• Frasa, M.A., Maximiano, F.C., Smolarczyk, K., Francis, R., Betson, M.E., Lozano, E., Goldenring, J., Seabra, M., Rak, A., Ahmadian, M.R. and Braga, V.M. (2010). Armus is a novel Rac1 effector protein that inactivates Rab7 and regulates E-cadherin stability at junctions. Curr. Biol. 20, 198-208
• Cirstea, I.C., Kutsche, K., Dvorsky, R., Gremer, L., Carta, C., Horn, D., Roberts, A.E., Lepri, F., Merbitz-Zahradnik, T., König, R., Kratz, C.P., Pantaleoni, F., Dentici, M.L., Joshi, V.A., Kucherlapati, R.S., Mazzanti, L., Mundlos, S., Patton, M., Cirillo Silengo, M., Rossi, C., Zampino, G., Digilio, C., Stuppia, L., Pennacchio, L.A., Gelb, B.D., Dallapiccola, B., Wittinghofer, A., Ahmadian, M.R., Tartaglia, M. and Zenker, M. (2010). A restricted spectrum of NRAS mutations causes Noonan syndrome. Nat. Genet. 42, 27-29.

Cooperators

• Carlier, Marie-France, Laboratoire d'Enzymologie, C.R.N.S., Gif-sur-Yvette, France
• McMahon, Harvey T., MRC Laboratories, Cambridge, UK
• Scheffzek, Klaus, EMBL, Strukturelle Biologie-Programme, Heidelberg
• Wittinghofer, Alfred, Max-Planck Institut für molekulare Physiologie, Dortmund