SBNet - Research Reports 1999

Bryan Finn

Position: "Forskare" (LU)

Project: Protein structure and dynamics

3.1a Protein Structure and Dynamics

3.1b Bryan E. Finn, Division of Physical Chemistry 2, Kemicentrum, Lund University.

Present co-workers: Houman Ghasriani, diploma student, fall '99; Eva Thulin, Lab engineer.

3.1c Two main projects are being pursued under this grant: [1] Structural and dynamical aspects of protein folding and [2] Structure, function and dynamics of a neuronal efficacy modulator.

[1] The first project deals with investigations of the mechanism by which the protein sequence information in one dimension is converted into the three-dimensional structure of a protein: i.e. the protein folding problem. The two systems being used for this study are the calcium-binding protein, calbindin D9k and calmodulin. These proteins are well characterised both structurally and dynamically by both NMR spectroscopy and X-ray crystallography. Both are composed of simple four-helix bundle structure and folds reversibly, making them excellent model systems for such studies. They are members of a family of closely related proteins, the co-called calmodulin superfamily or EF-hand superfamily, the latter name taken from the predominant folding motif of these proteins. In addition, a large number of mutants of both exist. During 1999 studies of the stability and folding mechanism of a domain of calmodulin, TR2C, was initiated. The study involves measurement of hydrogen exchange rates of the protein under various conditions in order to analyse the order of folding events. These studies are to be completed during the spring of 2000 at which time the results will be submitted for publication.

[2] The second project involves the determination of the structure of a 190 amino acid protein identified as a regulator of neural efficacy in Drosophila and later also isolated from mammals (rat, human). The protein has partial homology with the recently characterised photoreceptor proteins, recoverin and neurocalcin. In addition to sequence similarity, they shares properties of N-terminal acylation and calcium-dependent activity. The protein has been produced in large quantities with both 15N and 13C labeling by Dr. Finns collaborators, Prof. Olaf Pongs and Dr. Alexander Hauenschild of Hamburg University. The complete resonance assignment was carried out using data from a battery of 3- and 4-dimensional triple resonance experiments on our 600 MHz Varian Unity+ NMR spectrometer. An article on these results has been published in early 2000 (2). Structure calculation is also underway and we expect to complete the high-resolution structure of the protein in the near future. Future directions for the project will include studies of the effects of calcium-binding on the structure and activity of the protein. Birthe Kragelund, a post-doc working on the project during 1996-1998, has taken a position at the Carlsberg Laboratory in Copenhagen but continues to be a collaborator on the project.

While both projects have advanced at a reasonable pace and have been funded with regards to materials, both are hampered by a complete lack of personnel in the form of students and post-docs. Despite repeated attempts and generally positive reviews from the research councils, no funds have been provided for co-worker salaries. Regretfully, my own institution has also shown a lack of generosity in this regard as well. After deduction of local overhead costs, too little remains for even a single post-doc salary. The negative effect of this lack of support on the progress of the project was also pointed out in a recent International review of structural biology carried out by the NFR. Obviously, in the long-term, this jeopardises the successful completion of these projects.

3.1d Total budget (SBNet-related projects only) = 860 000 SEK

3.1e Budget for 1999 (Source; Project; Sum):

SSF (SBNet, salary: B. Finn); Protein Structure and dynamics; 560 000 SEK

SSF (cellular signalling special program, materials); Characterisation of neuroproteins; 300 000 SEK

4.1a Kragelund, B. B., Hauenschild, A., Carlström, G., Pongs, O. and Finn, B. E. (2000) 1H, 13C and 15N resonance assignments, secondary structure and fold of Ca2+-frequenin, a synaptic efficacy modulator. J. Biomol. NMR. 16,85.

4.1b Finn, B. E. and Drakenberg, T. (1999) Calcium binding proteins. Adv. Inorg. Chem.. 46, 441.

4.1c None

4.1d None

4.1e None

5.1 None

6.1 Prof. Olaf Pongs, Centre for Molecular Neurobiology, University of Hamburg, Germany

Dr. Birthe B. Kragelund, Dept of Molecular Biology, University of Copenhagen, Denmark

6.2 None

SBNet Latest update at 3 April, 2000.