Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.10.3.2 (laccase)
 4,656 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An electrochemical immunosensor based on a new detection principle was developed. Laccase, which is able to catalyse the electroreduction of oxygen via the direct (mediatorless) mechanism was used as an enzyme label. The new detection method does not require the presence of an electrochemically active mediator, and the reaction substrates are atmospheric oxygen and electrons, the latter being taken by the active site of the enzyme label directly from the electrode. The formation of the complex between laccase-labelled antibody and antigen on the electrode surface resulted in a considerable (more than 300 mV) shift of the electrode potential. The rate of the increase of the electrode potential was inversely proportional to the concentration of the free antigen in the sample. The non-specific adsorption of conjugate and other proteins on the electrode could be eliminated by using a polyethylenimine-based polymer on the electrode surface. Insulin was used as a model analyte. The sensitivity limit for this antigen was approximately 3 micrograms ml-1.
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PMID:A new approach to the construction of potentiometric immunosensors. 162 4

A new method of immunoelectrochemical analysis employing laccase as the enzyme label is described. The ability of the enzyme to catalyze electroreduction of oxygen via a direct mechanism allows the detection of the biospecific interaction of a laccase-labeled receptor, or antibody, with a ligand-modified electrode. Formation of a complex between the laccase-labeled antibody and the antigen on the electrode surface resulted in a considerable (greater than 300 mV) change in the electrode potential. Analysis was performed in a competitive scheme, and a single measurement could be made within 20 min in the absence of an electrochemically active mediator. The reaction substrates were atmospheric oxygen and electrons that were transferred directly from the electrode to the active site of the enzyme label. The use of a composite carbon material containing a polyethyleneimine-based polymer eliminated nonspecific interactions between the reaction components and the electrode surface. Insulin and mouse immunoglobulin were used as a model analytes.
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PMID:Immunopotentiometric electrodes based on bioelectrocatalysis in the absence of mediators. 184 Aug 41

The laccase induced gelation of maize bran arabinoxylans at 2.5% (w/v) in the presence of insulin or beta-lactoglobulin at 0.1% (w/v) was investigated. Insulin and beta-lacto-globulin did not modify either the gel elasticity (9 Pa) or the cross-links content (0.03 and 0.015 microg di- and triferulic acids/mg arabinoxylan, respectively). The protein release capability of the gel was also investigated. The rate of protein release from gels was dependent on the protein molecular weight. The apparent diffusion coefficient was 0.99 x 10(-7) and 0.79 x 10(-7) cm(2)/s for insulin (5 kDa) and beta-lactoglobulin (18 kDa), respectively. The results suggest that maize bran arabinoxylan gels can be potential candidates for the controlled release of proteins.
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PMID:Maize arabinoxylan gels as protein delivery matrices. 1938 79