Than Laboratory

Protein crystallography

Structure function relationship of proteins central to neurodegenerative diseases, aging and proteolytic (pro)protein processing

Projects

» Crystal structure of the entire E1-domain of APP. For more details see Dahms et al (2010) Proc. Natl. Acad. Sci. 107, 5381-5386

Alzheimer's Disease is the most frequent dementia worldwide, occurring predominantly in the elderly population. The disease-typical senile plaques contain as the main component the neurotoxic amyloid β-peptide (Aβ), which is proteolytically derived from the large type I transmembrane protein β-amyloid precursor prorein (APP). One key step is the cleavage of an intermediate inside the membrane by the large proteinase complex γ-secretase, finally liberating Aβ. While the overall processes leading to the formation of Aβ have been elucidated in many labs over the last years at the cell-biological and biochemical level, rather little is known about the detailed atomic structures of many involved molecules, their interactions and physiologic functions, setting the starting point for many research projects in our group.

 



» The movie shows the 3D structure of our pro-furin model, where the active site cleft of furin is blocked by the tightly bound pro- domain (white). For more details see Henrich et al (2005) J Mol Biol. 345, 211-227.
In eucaryotes, many secreted proteins and peptides are proteolytically excised from larger precursors by a specific class of serine proteases, the Proprotein/Prohormone Convertases (PCs). This cleavage is essential for the activation of the respective substrates, ranging from peptide hormones (such as insulin), extracellular proteases, growth and differentiation factors (implicated in neurodegenerative diseases, tumor growth and metastasis) to bacterial toxins and viral coat proteins, making the PCs a very interesting pharmacological target. Based on our crystal structure of furin and other studies of various groups, we are currently beginning to understand how furin and more generally this class of unusually specific endoproteinases recognize and cleave their substrates. In the future, we want to extend our structural understanding also to other family members, some of them showing quite different substrate specificities, and to push the rational structure-based development of inhibitors.

 

Our protein target oriented research often results in the necessity to establish, extend or to adapt new protein-crystallographic methods such as the development of an element-specific electron density map, calculated from anomalous differences collected at the K-absorption edge of calcium. This map unequivocally defined the exact number and spatial localization of Ca²⁺ ions bound to furin. In addition, we have used the transformation of protein crystals by tightly controlled humidity changes to improve the internal order of protein crystals, hereby enabling us to solve the respective structure.

The Research Group

Recent selected publications

• Dormann D, Rodde R, Edbauer D, Bentmann E, Fischer I, Hruscha A, Than ME, Mackenzie IR, Capell A, Schmid B, Neumann M, Haass C (2010) ALS-associated fused in sarcoma (FUS) mutations disrupt Transportin-mediated nuclear import. EMBO. [epub ahead of print]
• Dahms SO, Hoefgen S, Roeser D, Schlott B, Gührs K-H, Than ME (2010) Structure and Biochemical Analysis of the Heparin-induced E1-Dimer of the Amyloid Precursor Protein (APP). Proc Natl Acad Sci. 107, 5381-5386 [PubMed]
• Becker GL, Sielaff F, Than ME, Lindberg I, Routhier S, Day R, Lu Y, Garten W, Steinmetzer T (2010) Potent inhibitors of furin and furin-like proprotein convertases containing decarboxylated P1 arginine mimetics. J Med Chem. 53,1067-75 [PubMed]
• Henrich S, Lindberg I, Bode W, Than ME (2005) Proprotein convertase models based on the crystal structures of furin and kexin: explanation of their specificity. J Mol Biol. 345, 211-227. [PubMed]
• Than ME, Henrich S, Bourenkov GP, Bartunik HD, Huber R, Bode W (2005) The endoproteinase furin contains two essential Ca²⁺ ions stabilizing its N-terminus and the unique S1 specificity pocket. Acta Crystallogr D Biol Crystallogr. 61, 505-512. [PubMed]
• Henrich S, Cameron A, Bourenkov GP, Kiefersauer R, Huber R, Lindberg I, Bode W, Than ME (2003) The crystal structure of the proprotein processing proteinase furin explains its stringent specificity. Nat Struct Biol. 10, 520-526. [PubMed]
• Than ME, Henrich S, Huber R, Ries A, Mann K, Kühn K, Timpl R, Bourenkov GP, Bartunik HD, Bode W (2002) The 1.9 Å crystal structure of the noncollagenous (NC1) domain of human placenta collagen IV shows stabilization via a novel type of covalent Met-Lys cross-link. Proc Natl Acad Sci USA. 99, 6607-6612. [PubMed]
• Soulimane T, Buse G, Bourenkov GP, Bartunik HD, Huber R, Than ME (2000) Structure and mechanism of the aberrant ba(3)-cytochrome c oxidase from thermus thermophilus. EMBO J. 19, 1766-1776. [PubMed]