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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Controlling the molecular architecture of lactase immobilized in Langmuir-Blodgett films of phospholipids to modulate the enzyme activity

Full text
Author(s):
Ayoub, Fabio de Paula ; Caseli, Luciano
Total Authors: 2
Document type: Journal article
Source: COLLOIDS AND SURFACES B-BIOINTERFACES; v. 150, p. 8-14, FEB 1 2017.
Web of Science Citations: 10
Abstract

In this present work, the adsorption of the enzyme lactase onto Langmuir monolayers of the phospholipid dimyristoylphosphatidic acid (DMPA) was investigated and characterized with surface pressure-area isotherms, surface potential-area isotherms and polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS). The adsorption of the enzyme at the air-water interface expanded the lipid monolayer and increased the film compressibility at high surface pressures. Amide bands in the PM-IRRAS spectra were identified, with the C-N and C=O dipole moments lying parallel to the monolayer plane, revealing that the structuring of the enzyme into beta-sheets was kept in the mixed monolayer. The enzyme-lipid films were transferred from the floating monolayer to solid supports as Langmuir-Blodgett (LB) films and characterized with fluorescence spectroscopy and atomic force microscopy. The catalytic activity of the films was measured and compared to the homogenous medium. The enzyme accommodated in the LB films preserved more than 80% of the enzyme activity after 20 days, in contrast for the homogeneous medium, which preserved less than 60% of the enzyme activity. The method presented in this present work not only allows for an enhanced catalytic activity toward lactose, but also can help explain why certain film architectures exhibit better performance. (C) 2016 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 15/23446-0 - Smart surfaces: nanostructured and bioinspired systems for the investigation of molecular interactions in membrane models and for the production of devices for biosensors and environmental analysis
Grantee:Luciano Caseli
Support Opportunities: Regular Research Grants
FAPESP's process: 14/12557-2 - Multi-user equipment approved in grant 2013/14262-7: interfacial reometer
Grantee:Osvaldo Novais de Oliveira Junior
Support Opportunities: Multi-user Equipment Program