Computational Analysis of a Zn-Bound Tris(imidazolyl) Calix[6]arene Aqua Complex: Toward Incorporating Second-Coordination Sphere Effects into Carbonic Anhydrase Biomimetics

dc.contributor.authorEşsiz, Şebnem
dc.contributor.authorEşsiz, Şebnem
dc.contributor.authorWong, Sergio E.
dc.contributor.authorLau, Edmond Y.
dc.contributor.authorValdez, Carlos A.
dc.contributor.authorSatcher, Joe H. Jr.
dc.contributor.authorAines, Roger D.
dc.contributor.authorLightstone, Felice C.
dc.date.accessioned2019-06-27T08:03:40Z
dc.date.available2019-06-27T08:03:40Z
dc.date.issued2013
dc.departmentFakülteler, Mühendislik ve Doğa Bilimleri Fakültesi, Biyoinformatik ve Genetik Bölümüen_US
dc.description.abstractMolecular dynamics simulations and quantum-mechanical calculations were performed to characterize a supra-molecular tris(imidazolyl) calix[6]arene Zn2+ aqua complex as a biomimetic model for the catalyzed hydration of carbon dioxide to bicarbonate H2O + CO2 -> H+ + HCO3-. On the basis of potential-of-mean-force (PMF) calculations stable conformations had distorted 3-fold symmetry and supported either one or zero encapsulated water molecules. The conformation with an encapsulated water molecule is calculated to be lower in free energy than the conformation with an empty cavity (Delta G = 1.2 kcal/mol) and is the calculated free-energy minimum in solution. CO2 molecule partitioning into the cavity is shown to be very facile proceeding with a barrier of 1.6 kcal/mol from a weak encounter complex which stabilizes the species by about 1.0 kcal/mol. The stabilization energy of CO2 is calculated to be larger than that of H2O (Delta Delta G = 1.4 kcal/mol) suggesting that the complex will preferentially encapsulate CO2 in solution. In contrast the PMF for a bicarbonate anion entering the cavity is calculated to be repulsive in all nonbonding regions of the cavity due to the diameter of the calix[6]arene walls. Geometry optimization of the Zn-bound hydroxide complex with an encapsulated CO2 molecule showed that multiple noncovalent interactions direct the reactants into optimal position for nucleophilic addition to occur. The calixarene complex is a structural mimic of the hydrophilic/hydrophobic divide in the enzyme providing a functional effect for CO2 addition in the catalytic cycle. The results show that Zn-binding calix[6]arene scaffolds can be potential synthetic biomimetics for CO2 hydration catalysis both in terms of preferentially encapsulating CO2 from solution and by spatially fixing the reactive species inside the cavity.en_US]
dc.identifier.citation5
dc.identifier.doi10.1021/ct3008793en_US
dc.identifier.endpage1327
dc.identifier.issn1549-9618en_US
dc.identifier.issn1549-9618
dc.identifier.issue3
dc.identifier.pmid26587594en_US
dc.identifier.scopus2-s2.0-84874880879en_US
dc.identifier.scopusqualityN/A
dc.identifier.startpage1320en_US
dc.identifier.urihttps://hdl.handle.net/20.500.12469/825
dc.identifier.volume9en_US
dc.identifier.wosWOS:000316168700003en_US
dc.identifier.wosqualityQ1
dc.institutionauthorEşsiz, Şebnemen_US
dc.language.isoenen_US
dc.publisherAmer Chemical Socen_US
dc.relation.journalJournal Of Chemical Theory And Computationen_US
dc.relation.publicationcategoryMakale - Uluslararası Hakemli Dergi - Kurum Öğretim Elemanıen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.titleComputational Analysis of a Zn-Bound Tris(imidazolyl) Calix[6]arene Aqua Complex: Toward Incorporating Second-Coordination Sphere Effects into Carbonic Anhydrase Biomimeticsen_US
dc.typeArticleen_US
dspace.entity.typePublication
relation.isAuthorOfPublicationa83da4e2-c934-413a-886f-2438d0a3fd58
relation.isAuthorOfPublication.latestForDiscoverya83da4e2-c934-413a-886f-2438d0a3fd58

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