Structural and functional characterization of recombinant matrilin-3 A-domain and implications for human genetic bone diseases

Mutations in matrilin-3 result in multiple epiphyseal dysplasia (MED), which is characterized by delayed and irregular bone growth and early onset osteoarthritis. The majority of disease-causing mutations are located within the β-sheet of the single A-domain of matrilin-3, suggesting that they disrupt the structure and/or function of this important domain. Indeed, the expression of mutant matrilin-3 results in its intracellular retention within the rER of cells, where it elicits an unfolded protein response. In order to understand the folding characteristics of the matrilin-3 A-domain we determined its structure using circular dichroism, analytical ultracentrifugation and dual polarization interferometry. This study defined novel structural features of the matrilin-3 A-domain and identified a conformational change induced by the presence or the absence of Zn(2+). In the presence of Zn(2+) the A-domain adopts a more stable ‘tighter’ conformation. However, after the removal of Zn(2+) a potential structural rearrangement of the MIDAS motif occurs, which leads to a more ‘relaxed’ conformation. Finally, in order to characterize the interactions of the matrilin-3 A-domain we performed binding studies on a BIAcore using type II & IX collagen and COMP. We were able to demonstrate that it binds to type II & IX collagen and COMP in a Zn(2+)-dependent manner. Furthermore, we have also determined that the matrilin-3 A-domain appears to bind exclusively to the COL3 domain of type IX collagen and that this binding is abolished in the presence of a disease causing mutation in type IX collagen

eLearning in industrial mathematics with applications to nanoelectronics

The main topic of this chapter is a detailed exposition of CoMSON's attempt to give a contribution in the synergetic process of integration of research and training between Academia and Industry