INTERACTIONS OF N-TERMINUS OF HUMAN RECOMBINANT FIBRILLIN-3 WITH FIBULIN-2 AND HEPARIN.

Fibrillins are large family of proteins that form a major constituent of microfibrils and subsequently the extracellular matrix. Fibrillin-1 is the most characterized fibrillin member and has been verified to be linked to Marfan syndrome. Fibrillin-2 was linked to congenital contractural arachnodactyly. Fibrillin-3 is expressed during tissues development and it has been linked to Weill Marchesani syndrome and polycystic ovary syndrome. Self-assembly and multiple ligand binding properties of fibrillins are crucial for the proper formation and function of microfibrils. These properties are often compromised in pathological situations. Therefore, we aimed to study the interaction epitopes of the N-terminal of fibrillin-3 with fibulin-2 and heparin in comparison to fibrillin-1, as well as the molecular shapes of the N-terminal region of fibrillin-3. In the present study we compared the binding of fibulin-2 and heparin to the N-terminal polypeptides of both fibrilin-1 and fibrillin-3. Also, we compared folding shapes of their N-termini. Our results indicated the similarity of N-termini of both fibrillin-1 and fibrillin-3 in binding to fibulin-2 and heparin as well as their structures. The N-terminal polypeptides of Fibrillin-3 can interact with Fibulin-2 and heparin in a similar fashion as compared to fibrillin-1, indicating similar functions for both isoforms.