title: Acylated Carrageenan Changes the Physicochemical Properties of Mixed Enzyme-Lipid Ultrathin Films and Enhances the Catalytic Properties of Sucrose Phosphorylase Nanostructured as Smart Surfaces.
abstract: Control over the catalytic activity of enzymes is important to construct biosensors with a wide range of detectability and higher stability. For this, immobilization of enzymes on solid supports as nanostructured films is a current approach that permits easy control of the molecular architecture as well as tuning of the properties. In this article, we employed acylated carrageenan (AC) mixed with phospholipids at the air-water interface to facilitate the adsorption of the enzyme sucrose phosphorylase (SP). AC stabilized the adsorption of SP at the phospholipid monolayer, as detected by tensiometry, by which thermodynamic parameters could be inferred from the surface pressure-area isotherm. Also, infrared spectroscopy applied in situ over the monolayer showed that the AC-phospholipid system not only permitted the enzyme to be adsorbed but also helped conserve its secondary structure. The mixed monolayers were then transferred onto solid supports as Langmuir-Blodgett (LB) films and investigated with transfer ratio, quartz crystal microbalance, fluorescence spectroscopy, and atomic force microscopy. The enzyme activity of the LB film was then determined, revealing that although there was an expected reduction in activity in relation to the homogeneous environment the activity could be better preserved after 1 month, revealing enhanced stability.
authors.affiliation: Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of Sao Paulo , Diadema, SP 04021-001, Brazil.
authors.forename: Jefferson M
authors.initials: JM
authors.lastname: Rocha
authors.affiliation: São Carlos Physics Institute, University of São Paulo , São Carlos, SP 13566-590, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Pavinatto
authors.affiliation: São Carlos Physics Institute, University of São Paulo , São Carlos, SP 13566-590, Brazil.
authors.forename: Thatyane M
authors.initials: TM
authors.lastname: Nobre
authors.affiliation: Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of Sao Paulo , Diadema, SP 04021-001, Brazil.
authors.forename: Luciano
authors.initials: L
authors.lastname: Caseli
mesh_terms: D000215:Acylation; D000388:Air; D055162:Biocatalysis; D002351:Carrageenan / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D005964:Glucosyltransferases / Q000737:chemistry / Q000378:metabolism*; D000070007:Leuconostoc mesenteroides / Q000201:enzymology; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D010743:Phospholipids; D014867:Water; D002351:Carrageenan; D005964:Glucosyltransferases; C025901:sucrose phosphorylase