title: Molecular dynamics study of the conformational stability of esterase 2 from Alicyclobacillus acidocaldarius.
abstract: Circular dichroism and differential scanning calorimetry measurements showed that esterase 2 from the thermophilic microorganism Alicyclobacillus acidocaldarius, EST2, and its variant in which the first 35 residues have been deleted, EST2-36 del, unfold reversibly on increasing temperature, and possess two cooperative and coupled domains [12]. Structural features of the α/β hydrolase fold of EST2, with nine α-helices packed against the central twisted β-sheet, do not allow a straightforward identification of these two cooperative and coupled domains. Molecular dynamics simulations, each one 20 ns long, have been performed at 300, 400 and 500 K, on both proteins in explicit water. Suitable analysis of MD trajectories has allowed a reliable identification of the two cooperative domains (i.e., the less stable one corresponds to external α-helices, whereas the more stable one corresponds to the central twisted β-sheet) and the attribution of the key coupling role to the last and long α-helix of EST2.
authors.affiliation: Dipartimento di Scienze Farmaceutiche e Biomediche, Università di Salerno, Via Ponte Don Melillo, 84084 Fisciano, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Pagano
authors.forename: Pompea
authors.initials: P
authors.lastname: Del Vecchio
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Mattia
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Graziano
mesh_terms: D056450:Alicyclobacillus / Q000737:chemistry / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D004795:Enzyme Stability; D004950:Esterases / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D004950:Esterases