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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.)

Rhodanese incorporated in Langmuir and Langmuir-Blodgett films of dimyristoylphosphatidic acid: Physical chemical properties and improvement of the enzyme activity

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Author(s):
de Araujo, Felipe Tejada [1] ; Caseli, Luciano [1]
Total Authors: 2
Affiliation:
[1] Univ Fed Sao Paulo, Inst Environm Chem & Pharmaceut Sci, Diadema, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: COLLOIDS AND SURFACES B-BIOINTERFACES; v. 141, p. 59-64, MAY 1 2016.
Web of Science Citations: 8
Abstract

Preserving the catalytic activity of enzymes immobilized in bioelectronics devices is essential for optimal performance in biosensors. Therefore, ultrathin films in which the architecture can be controlled at the molecular level are of interest. In this work, the enzyme rhodanese was adsorbed onto Langmuir monolayers of the phospholipid dimyristoylphosphatidic acid and characterized by surface pressure area isotherms, polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS), and Brewster angle microscopy (BAM). The incorporation of the enzyme (5% in mol) in the lipid monolayer expanded the film, providing small surface domains, as visualized by BAM. Also, amide bands could be identified in the PM-IRRAS spectra, confirming the presence of the enzyme at the air-water interface. Structuring of the enzyme into alpha-helices was identified in the mixed monolayer and was preserved when the film was transferred from the liquid interface to solids supports as Langmuir-Blodgett (LB) films. The enzyme-lipid LB films were then characterized by fluorescence spectroscopy, PM-IRRAS, and atomic force microscopy. Measurements of the catalytic activity towards cyanide showed that the enzyme accommodated in the LB films preserved more than 87% of the enzyme activity in relation to the homogeneous medium. After 1 month, the enzyme in the LB film maintained 85% of the activity in contrast to the homogeneous medium, which 24% of the enzyme activity was kept. The method presented in this work not only points to an enhanced catalytic activity toward cyanide, but also may explain why certain film architectures exhibit an improved performance. (C) 2016 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 13/10213-1 - Interaction of bioactive materials in ultrathin films organized in models for biointerfaces models for investigation of molecular recognition processes and associated molecular mechanisms
Grantee:Luciano Caseli
Support Opportunities: Regular Research Grants