title: Carbonic anhydrase-mimetic bolaamphiphile self-assembly for CO2 hydration and sequestration.
abstract: A biomimetic catalyst was prepared through the self-assembly of a bolaamphiphilic molecule with histidine moieties for the sequestration of carbon dioxide. The histidyl bolaamphiphilic molecule bis(N-α-amidohistidine)-1,7-heptane dicarboxylate has been synthesized and self-assembled to produce analogues of the active sites of carbonic anhydrase (CA) after association with Zn(2+) ions. Spectroscopic analysis demonstrated the coordination of the Zn(2+) ions with histidine imidazole moieties, which is the core conformation of CA active sites. The Zn-associated self-assembly worked as a CA-mimetic catalyst that shows catalytic activity for CO2 hydration. Evaluation of the kinetics of using para-nitrophenylacetate revealed that the kinetic parameters of the CA-mimetic catalyst were maximized at the optimal Zn concentration and that excess Zn ions resulted in deteriorated catalytic activity. The performance of the CA-mimetic catalyst was enhanced by changing the pH value and temperature of the reaction, which implies that the hydrolysis of the substrate is the rate-determining step. The catalyst-assisted sequestration of CO2 was demonstrated by CaCO3 precipitation upon the addition of Ca(2+) ions. This study offers an easy way to prepare enzyme analogues for CO2 sequestration through the self-assembly of bolaamphiphile molecules with designer biochemical moieties.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120749 (Korea), Fax: (+82) 2-312-6401.
authors.forename: Min-Chul
authors.initials: MC
authors.lastname: Kim
authors.forename: Sang-Yup
authors.initials: SY
authors.lastname: Lee
mesh_terms: D001669:Biochemical Phenomena; D032701:Biomimetics / Q000379:methods; D002245:Carbon Dioxide / Q000737:chemistry*; D002256:Carbonic Anhydrases / Q000737:chemistry*; D002384:Catalysis; D005663:Furans / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011728:Pyridones / Q000737:chemistry*; D013696:Temperature
chemical_list: D005663:Furans; D011728:Pyridones; C543575:bolaamphiphile; D002245:Carbon Dioxide; D006639:Histidine; D002256:Carbonic Anhydrases
keywords: amphiphiles; carbon dioxide; enzyme catalysis; self-assembly; sequestration