Early Polarographic Studies on Proteins

Abstract

The first effects of proteins observed with the dropping mercury electrode were catalytic, due to evolution of hydrogen in weakly alkaline solutions. Catalytic lowering of hydrogen overvoltage in presence of cobalt ions, the socalled Brdicka reaction, became the main means for polarographic study of proteins. Apart from that, polarography has been used for following proteins in their adsorption on the electrode surface, in their anodic reaction with mercury at positive potentials, in reduction of the disulfidic bonds of their components, in their complexation with metallic ions in the solution, in electrode reactions of their prosthetic groups and in antigen-antibody interactions. Our review is limited to applications of the dropping mercury electrode.

Electroactive Centers inEuphorbiaLatex and Lentil Seedling Amine Oxidases

“…This is may be due to the simultaneous occurrence of a hydrogen evolution reaction via presodium catalysis. 22) Since the enzymes did not have any other electro-reactive center and disulfide bridges were not accessible (see below), the second reduction peak (C2 in Figs. 1 and 2) might be related to the reduction in TPQ occurring for both native and copperdepleted enzymes, because the dithionite procedure removes only the metal center of the enzymes.…”

Temperature Effect on Binding Affinity and Stoichiometry Between Some Steroids and Human Serum Albumin

“…[61][62][63][64] Moreover, it is well known that cystine contained in many proteins undergoes polarographic electroreduction of its-S-S-bond at potential of about -0.7 V (vs. SCE) in neutral buffer solutions. 65 As can be seen in Fig. 2 (Inset), the difference between anodic and cathodic peak potentials (DE p = E pa -E pc = 40 mV) refers to an electrochemical processes involving the transfer of about two electrons.…”

Square Wave Voltammetric Label‐free Determination of the Natural Protein Material Silk Fibroin

“…It is widely applied to determination of proteins for many years since the first papers on polarography of proteins were reported at the beginning of the 1930's. 7,8 For proteins containing cysteine/cystine, their electrochemical signals can be used for quantitative determination based on the formation of Hg-S bonds, 9 the reduction of disulfide groups, 10 and the catalytic evolution of hydrogen 11,12 on mercury electrodes. However, those proteins containing tyrosine and/or tryptophan residues can be oxidized at a carbon electrode.…”