Biomaterial Database

Electrochemical and glucose oxidase coenzyme activity of flavin adenine dinucleotide covalently attached to glassy carbon at the adenine amino group. 1985

O Miyawaki, and L B Wingard

Flavin adenine dinucleotide (FAD) was covalently attached to an electron-conducting support, i.e., glassy carbon. The support was activated by oxidation to create surface carboxylic acid groups, followed by reaction with a water-soluble carbodiimide. FAD was then attached to the activated support by three different methods: (1) directly; (2) through 6-aminocaproic acid as a spacer; and (3) through ethylenediamine glutaraldehyde as a spacer. Coupling occurred at the FAD adenine amino group, or possibly at a ribityl OH group. Cyclic voltammetry was used to determine Eo' values and FAD loadings. The immobilized FAD also acted as a catalyst for the oxidation of reduced nicotinamide adenine dinucleotide (NADH) in that it reduced overpotential by about 195 mV. When the apoenzyme of glucose oxidase was added to the glassy carbon-FAD or glassy carbon-spacer-FAD preparations, no reconstitution of enzyme activity could be observed. This suggests strongly that the adenine amino group of FAD cannot be modified by attachment of something as large as easily visible solid particles. However, it leaves unanswered the question of larger molecular weight material can be accommodated in the FAD-apoenzyme cleft and retain glucose oxidase activity.

UI	MeSH Term	Description	Entries
D009243	NAD	A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)	Coenzyme I,DPN,Diphosphopyridine Nucleotide,Nadide,Nicotinamide-Adenine Dinucleotide,Dihydronicotinamide Adenine Dinucleotide,NADH,Adenine Dinucleotide, Dihydronicotinamide,Dinucleotide, Dihydronicotinamide Adenine,Dinucleotide, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide,Nucleotide, Diphosphopyridine
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D002244	Carbon	A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.	Carbon-12,Vitreous Carbon,Carbon 12,Carbon, Vitreous
D004563	Electrochemistry	The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.	Electrochemistries
D004579	Electron Transport	The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)	Respiratory Chain,Chain, Respiratory,Chains, Respiratory,Respiratory Chains,Transport, Electron
D005182	Flavin-Adenine Dinucleotide	A condensation product of riboflavin and adenosine diphosphate. The coenzyme of various aerobic dehydrogenases, e.g., D-amino acid oxidase and L-amino acid oxidase. (Lehninger, Principles of Biochemistry, 1982, p972)	FAD,Flavitan,Dinucleotide, Flavin-Adenine,Flavin Adenine Dinucleotide
D005898	Glass	Hard, amorphous, brittle, inorganic, usually transparent, polymerous silicate of basic oxides, usually potassium or sodium. It is used in the form of hard sheets, vessels, tubing, fibers, ceramics, beads, etc.
D005949	Glucose Oxidase	An enzyme of the oxidoreductase class that catalyzes the conversion of beta-D-glucose and oxygen to D-glucono-1,5-lactone and peroxide. It is a flavoprotein, highly specific for beta-D-glucose. The enzyme is produced by Penicillium notatum and other fungi and has antibacterial activity in the presence of glucose and oxygen. It is used to estimate glucose concentration in blood or urine samples through the formation of colored dyes by the hydrogen peroxide produced in the reaction. (From Enzyme Nomenclature, 1992) EC 1.1.3.4.	Microcid,Oxidase, Glucose
D000327	Adsorption	The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.	Adsorptions
D001051	Apoenzymes	The protein components of enzyme complexes (HOLOENZYMES). An apoenzyme is the holoenzyme minus any cofactors (ENZYME COFACTORS) or prosthetic groups required for the enzymatic function.	Apoenzyme