Heparin and heparan sulfate (HS) are highly sulfated polysaccharides belonging to the glycosaminoglycan (GAG) family. They consist of repeating disaccharide units that include uronic acid and glucosamine. Exogenous heparin, derived from porcine or bovine tissues, is used as an anticoagulant drug and its therapeutic activity is primarily attributed to the binding and activation of antithrombin (AT). Heparan sulfate (HS), expressed on the cell surface and in the extracellular matrix, is involved in numerous physiological and pathological processes. It interacts with several proteins, including the spike (S) protein that drives the early stage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the heparanase (HPSE) enzyme, whose overexpression induces tumor growth and spread. In this thesis, nuclear magnetic resonance (NMR) experiments and computational methods were applied to gain molecular insights into the recognition process of heparin by AT. The combined use of NMR spectroscopy and in silico methodologies also allowed to define the structural and conformational features underlying both the interaction of HS with the SARS-CoV-2 S protein and the binding of HS mimetics to HPSE.
L’eparina e l’eparan solfato (HS) sono polisaccharidi solfatati appartenenti alla famiglia dei glicosaminoglicani (GAG). Sono composti da unità disaccaridiche ripetute di acido uronico e glucosammina. L’eparina esogena, estratta dalla mucosa di intestino suino o di polmone bovino, è usata come farmaco anticoagulante e la sua attività è principalmente correlata al legame e all’attivazione dell’antitrombina (AT). L’HS presente sulla superficie cellulare e nella matrice extracellulare è coinvolto in numerosi processi fisiologici e patologici. Esso interagisce con diverse proteine, tra cui la proteina spike implicata nella infezione da SARS-CoV-2 e l’enzima eparanasi, la cui sovraespressione è associata allo sviluppo e alla crescita di neoplasie. In questo lavoro di tesi, esperimenti di risonanza magnetica nucleare (NMR) e metodi computazionali sono stati applicati al fine di approfondire il meccanismo di riconoscimento molecolare dell’eparina da parte dell’AT. L’uso combinato di spettroscopia NMR e metodologie in silico ha inoltre permesso di analizzare gli aspetti strutturali e conformazionali alla base dell’interazione dell’HS con la proteina spike del SARS-CoV-2 e del legame tra mimetici dell’HS e l’eparanasi.
NMR AND IN SILICO APPROACHES FOR INVESTIGATING PROTEIN-GLYCOSAMINOGLYCAN INTERACTIONS
PARAFIORITI, MICHELA
2024-01-25
Abstract
Heparin and heparan sulfate (HS) are highly sulfated polysaccharides belonging to the glycosaminoglycan (GAG) family. They consist of repeating disaccharide units that include uronic acid and glucosamine. Exogenous heparin, derived from porcine or bovine tissues, is used as an anticoagulant drug and its therapeutic activity is primarily attributed to the binding and activation of antithrombin (AT). Heparan sulfate (HS), expressed on the cell surface and in the extracellular matrix, is involved in numerous physiological and pathological processes. It interacts with several proteins, including the spike (S) protein that drives the early stage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the heparanase (HPSE) enzyme, whose overexpression induces tumor growth and spread. In this thesis, nuclear magnetic resonance (NMR) experiments and computational methods were applied to gain molecular insights into the recognition process of heparin by AT. The combined use of NMR spectroscopy and in silico methodologies also allowed to define the structural and conformational features underlying both the interaction of HS with the SARS-CoV-2 S protein and the binding of HS mimetics to HPSE.File | Dimensione | Formato | |
---|---|---|---|
Parafioriti-PhD-Thesis.pdf
accesso aperto
Descrizione: Tesi di Dottorato di Michela Parafioriti
Tipologia:
Tesi di dottorato
Dimensione
37.74 MB
Formato
Adobe PDF
|
37.74 MB | Adobe PDF | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.