The methylthiotransferases (MTTases) represent a subfamily of the S-adenosylmethionine (AdoMet) radical superfamily of enzymes that catalyze the attachment of a methylthioether (-SCH3) moiety on unactivated carbon centers. These enzymes contain two [4Fe-4S] clusters, one of which participates in the reductive fragmentation of AdoMet to generate a 5'-deoxyadenosyl 5'-radical and the other of whi...

Electrochemistry and cell signaling are widely involved in the operation of biochemical systems. This article discusses the relationship of the two, as well as interconnection with a variety of other aspects, such as free radicals, receptors, and stereochemistry. Both endogenous and exogenous agents are involved. The electrochemistry deals with electrostatics, electron transfer, reduction poten...

A novel amperometric nitrite (NO2 − ) sensor was developed based on immobilization of hemoglobin (Hb) on a graphene nanosheet modified electrode by chitosan-N, N-Dimethylformamide (CS-DMF) hydrogel. The surface morphologies of the modified electrode were characterized by SEM, and direct electrochemistry of Hb on the graphene nanosheet-based electrode were investigated by cyclic voltammetry. The...

A novel third-generation hydrogen peroxide (H(2)O(2)) biosensor was developed by immobilizing horseradish peroxidase (HRP) on a biocompatible attapulgite (ATP) modified glassy carbon (GC) electrode. The ATP could provide a biocompatible microenvironment for enzyme molecules, greatly amplify the coverage of HRP molecules on the electrode surface, and most importantly facilitate the direct electr...

E. coli cells evolved under electrochemical tension in a microbial fuel cell possess direct electrochemical behavior due to the excretion of hydroquinone derivatives through a highly permeable outer membrane, and their catalyzed fuel cell demonstrates excellent performance.

By using ionic liquid 1-hexylpyridinium hexafluorophosphate (HPPF6) based carbon ionic liquid electrode (CILE) as the substrate electrode, a CoMoO4 nanorods and myoglobin (Mb) composite was casted on the surface of CILE with chitosan (CTS) as the film forming material to obtain the modified electrode (CTS/ CoMoO4-Mb/CILE). Spectroscopic results indicated that Mb retained its native structures w...

The redox protein and enzyme, such as hemoglobin (Hb), horseradish peroxidase (HRP) and glucose oxidase (GOx), was immobilized on the surface of the carbon nanotube modified glassy carbon (CNT/GC) electrode, respectively. The cyclic voltammetric results indicated that the redox protein and enzyme underwent effective and stable direct electron transfer reaction with a pair of nearly symmetrical ...

A patterning method termed "RIPPLE" (reactive interface patterning promoted by lithographic electrochemistry) is applied to the fabrication of arrays of dielectric and metallic optical elements. This method uses cyclic voltammetry to impart patterns onto the working electrode of a standard three-electrode electrochemical setup. Using this technique and a template stripping process, periodic arr...

The key characteristics of multicopper oxidases are redox potentials of Type 1, Type 2 and Type 3 copper centers of enzymes. However, there is still a challenge to obtain a value of the redox "signature" of the enzymes. In this study, the electrochemical behavior of T1 and T2/T3 redox copper centers of bilirubin oxidase (BOD) from the fungi Myrothecium verrucaria was studied based on direct bio...

Two genetically distinct flavodoxins, designated AcFldA and AcFldB, were isolated from Azotobacter chroococcum (MCD1155) grown under nitrogen-fixing conditions. AcFldA and AcFldB differ in their midpoint potentials for the semiquinone-hydroquinone couple (Em -305 mV and -520 mV respectively). Only AcFldB was competent to act as an electron donor to the Mo-containing nitrogenase of A. chroococcu...