Effect of interfering agents for urease immobilized in Langmuir-Blodgett films of controlled molecular architecture

Author(s)

Rodrigues, Raul Torres ^[1] ; Souza Nordi, Cristiana Freire ^[1] ; Siqueira Junior, Jose Roberto ^[2] ; Caseli, Luciano ^[1]

Affiliation

^[1] Fed Univ Sao Paulo UNIFESP, Inst Environm Chem & Pharmaceut Sci, Diadema, SP - Brazil

^[2] Fed Univ Triangulo Mineiro UFTM, Inst Nat Exact Sci & Educ, Uberaba, MG - Brazil

• Document type: Journal article
• Source: Thin Solid Films; v. 704, JUN 30 2020.
• Web of Science Citations: 0

Abstract

Catalytic performance of enzymes confined in lipid Langmuir-Blodgett (LB) films can be tuned if the molecular architecture and environment are controlled. In this paper, nanohybrid LB films constituted of dioctadecyldimethylammonium bromide, algal polysaccharides, carbon nanotubes and urease had its catalytic activity investigated by adding possible interfering ions in the aqueous environment that contained urea in contact with the LB film. Catalytic activity of LB film towards urea hydrolysis was treated as obeying the Michaelis-Menten mechanism and the effect of ascorbate, oxalate, sulfate, phosphate and their respective counterions were measured. While oxalate and ascorbic acid inactivated totally the catalytic activity, sodium, potassium, sulfate and phosphate ions inhibited only partially. Therefore, these experiments gave us insight about the mechanism of enzymes confined in ultrathin films for biosensing. (AU)

• FAPESP's process: 19/03239-0 - Nanostructured interfaces for the investigation of bioactive substances in cell membrane models and for the construction of optoelectronic devices
• Grantee: Luciano Caseli
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/01867-6 - Hybrid Langmuir-Blodgett film of carbon nanotubes and algal polysaccharides to immobilize enzymes
• Grantee: Raul Torres Rodrigues
• Support Opportunities: Scholarships in Brazil - Scientific Initiation