ADDRESSING THE MOLECULAR BASIS OF THE INTERACTION BETWEEN GLYCOSAMYNOGLYCAN, MIMETICS AND PROTEINS

Glycosaminoglycans (GAGs) are some of the most relevant biological molecules, involved in important biological, physiological activities and also used as pharmaceutical agents. GAG research activities oriented to understand their nature, molecular population composition, characterisation, protein-GAG interaction network and putative pharmaceutical properties are essential to develop new drug with a more controlled and described activity. Recently experimental and clinical informations had increased the attention over heparan sulfate (HS)/ heparin (Hep) coagulant and not coagulant activity opening new fields of research oriented to develop new therapeutical strategy involving heparin usage. Hep mimetics/dericvatives can be extremely helpful from this perspective, due to their controlled nature, molecular features and structure, thus they can be employed as performance drugs. My Ph.D. thesis deals with statistical characterisation of commercial and not commercial pharmaceutical heparin, composition and structural characterisation of heparin mimetics and characterisation of protein-heparin interaction for drug design strategy. Thesis focus was oriented on three different subject: 1) build a library of accepted and well charaterised heparins, set up a statistical analysis based on a principal component analysis (PCA) approach to statistically define heparin molecular nature and to develop a new heparin quality control procedure. 2) 1D/2D NMR interaction studies (1H, TOCSY, NOESY, ROESY, trNOE and STD) to understand the importance of heparin antithrombin (AT) binding domain (AT-bd, the pentasaccharide β-D-N-acetylated,6-O-sulfated glucosamine -α(1->4)-D-glucuronic acid -β(1->4)-D-N-sulfated,3,6-O-sulfated glucosamine -α(1->4)-D-2-O-sulfated iduronic acid -α(1->4)-D-N-sulfated,6-O-sulfated glucosamine, also abbreviated as AGA*IA) flanking residues over AT activation on octasaccharides bearing the pentasaccharide sequence with normal or modified reducent residue in complex with AT. 3) dynamic light scattering (DLS) studies on amyloid beta 1-40 (Aβ1-40)-heparin or heparin mimetics/derivatives as a new strategy to counter act Aβ aggregation progression involved in Alzheimer disease (AD) and better understand the deep relationship between Aβ peptide and GAGs.