title: Role of hydration in collagen recognition by bacterial adhesins.
abstract: Protein-protein recognition regulates the vast majority of physiological or pathological processes. We investigated the role of hydration in collagen recognition by bacterial adhesin CNA by means of first principle molecular-dynamics samplings. Our characterization of the hydration properties of the isolated partners highlights dewetting-prone areas on the surface of CNA that closely match the key regions involved in hydrophobic intermolecular interactions upon complex formation, suggesting that the hydration state of the ligand-free CNA predisposes the protein to the collagen recognition. Moreover, hydration maps of the CNA-collagen complex reveal the presence of a number of structured water molecules that mediate intermolecular interactions at the interface between the two proteins. These hydration sites feature long residence times, significant binding free energies, and a geometrical distribution that closely resembles the hydration pattern of the isolated collagen triple helix. These findings are striking evidence that CNA recognizes the collagen triple helix as a hydrated molecule. For this structural motif, the exposure of several unsatisfied backbone carbonyl groups results in a strong interplay with the solvent, which is shown to also play a role in collagen recognition.
authors.affiliation: Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerce (IBB-CNR), Naples, Italy. luigi.vitagliano@unina.it
authors.forename: Luigi
authors.initials: L
authors.lastname: Vitagliano
authors.forename: Rita
authors.initials: R
authors.lastname: Berisio
authors.forename: Alfonso
authors.initials: A
authors.lastname: De Simone
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry / Q000378:metabolism*; D001059:Apoproteins / Q000737:chemistry / Q000378:metabolism; D003094:Collagen / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018360:Crystallography, X-Ray; D056004:Molecular Dynamics Simulation; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification; D055550:Protein Stability; D017433:Protein Structure, Secondary; D013211:Staphylococcus aureus / Q000378:metabolism; D014867:Water / Q000737:chemistry*
chemical_list: D018829:Adhesins, Bacterial; D001059:Apoproteins; D010455:Peptides; D014867:Water; D003094:Collagen