Surface Chemistry Studies on the Formation of Mixed Stearic Acid/Phenylalanine Dehydrogenase Langmuir and Langmuir-Blodgett Films

Autor(es)

Cruz Gomes da Silva, Rafael Leonardo ^[1] ; Sharma, Shiv K. ^[2] ; Paudyal, Suraj ^[2] ; Mintz, Keenan J. ^[2] ; Leblanc, Roger M. ^[2] ; Caseli, Luciano ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Chem, BR-09920540 Diadema, SP - Brazil

^[2] Univ Miami, Dept Chem, Coral Gables, FL 33146 - USA

• Tipo de documento: Artigo Científico
• Fonte: Langmuir; v. 37, n. 25, p. 7771-7779, JUN 29 2021.
• Citações Web of Science: 0

Resumo

This work investigates the physicochemical properties of mixed stearic acid (HSt)/phenylalanine dehydrogenase enzyme (PheDH) Langmuir films and their immobilization onto solid supports as Langmuir-Blodgett (LB) films. PheDH from the aqueous subphase enters the surfactant matrix up to an exclusion surface pressure of 25.3 mN/m, leading to the formation of stable and highly condensed mixed Langmuir monolayers. Hydrophobic interactions between the enzyme and HSt nonpolar groups tuned the secondary structure of PheDH, evidenced by the presence of beta-sheet structures as demonstrated by infrared and circular dichroism spectra. The floating monolayers were successfully transferred to solid quartz supports, yielding Y-type LB films, and then characterized employing fluorescence, circular dichroism, and microscopic techniques, which indicated that PheDH was co-immobilized with HSt proportionally to the number of transferred layers. The enzyme fluidized the HSt monolayers, reducing their maximum dipoles when condensed to their maximum, and disorganized the alkyl chains of the fatty acid, as detected with infrared spectroscopy. The stability of the mixed floating monolayers enabled their transfer to solid supports as LB films, which is important for producing optical and electrochemical sensors for phenylalanine whose molecular architecture can be controlled with precision. (AU)

• Processo FAPESP: 19/01797-6 - Filmes de Langmuir e Langmuir-Blodgett de lipídios contendo fenilalanina desidrogenase para biossensores de fenilalanina
• Beneficiário: Rafael Leonardo Cruz Gomes da Silva
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Mestrado
• Processo FAPESP: 18/22214-6 - Rumo à convergência de tecnologias: de sensores e biossensores à visualização de informação e aprendizado de máquina para análise de dados em diagnóstico clínico
• Beneficiário: Osvaldo Novais de Oliveira Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 18/00291-9 - Filmes de Langmuir e Langmuir-Blodgett de lipídios contendo fenilalanina desidrogenase para sensores de fenilalanina
• Beneficiário: Rafael Leonardo Cruz Gomes da Silva
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 19/03239-0 - Interfaces nanoestruturadas para a investigação de substâncias bioativas em modelos de membrana celular e para a construção de dispositivos optoeletrônicos enzimáticos
• Beneficiário: Luciano Caseli
• Modalidade de apoio: Auxílio à Pesquisa - Regular