title: Electrochemical detection of transketolase activity using a tyrosinase biosensor.
abstract: This paper proposes a new concept of transketolase (TK) activity profiling. A tyrosinase (PPO) biosensor, based on the immobilization of this enzyme in a Mg(2)Al-Cl layered double hydroxide, was developed for the amperometric detection of N-acetyl-l-tyrosine ethyl ester monohydrate (N-Ac-Tyr-OEt) at -0.2V. This compound was released during an enzymatic reaction catalyzed by TK with N-acetyl-O-(2R, 3S, 5-trihydroxy-4-oxopentyl)-l-tyrosine ethyl ester used as donor substrate. This tyrosinase biosensor was optimized for the detection of TK activity, including PPO optimum substrate concentration, electrolyte nature, pH, and influence of bovine serum albumin (BSA). It was found that N-Ac-Tyr-OEt release is dependent on TK concentration (U/mL) in the electrolyte medium. These results demonstrate the sensitivity and specificity of the tyrosinase biosensor designed for in vitro detection of TK activity, which is known to be involved in several diseases.
authors.affiliation: Sección Departamental Química Analítica, Facultad de Farmacia, Universidad Complutense, Madrid, Spain.
authors.forename: Marta Sanchez-Paniagua
authors.initials: MS
authors.lastname: Lopez
authors.forename: Franck
authors.initials: F
authors.lastname: Charmantray
authors.forename: Virgil
authors.initials: V
authors.lastname: Helaine
authors.forename: Laurence
authors.initials: L
authors.lastname: Hecquet
authors.forename: Christine
authors.initials: C
authors.lastname: Mousty
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004789:Enzyme Activation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D014174:Transketolase / Q000032:analysis* / Q000737:chemistry*
chemical_list: D014442:Monophenol Monooxygenase; D014174:Transketolase