Mercury compounds, organic behavioral effects

The behavior of aspartate carbamoylase changed dramatically when the enzyme was treated with the organic mercurial compound p-hydroxymercuribenzoate (see fig. 9.14). The binding of aspartate no longer showed positive cooperativity, and ATP or CTP were without effect. Exposure to mercurials was found to cause the enzyme to dissociate into two types of fragments, one of which retained the enzymatic activity but was no longer affected by CTP or... 

Linear organomercurials provide a convenient basis for the investigation of the effect of substitution in the organic moiety on the metal chemical shift. In view of significant solvent effects, it is desirable to measure any such series of compounds in more than one solvent. Increases in the shielding of ca. 150 ppm are observed for each substitution of Me for an a-H in Hg-CHj derivatives, while smaller decreases in shielding (ca. 30 ppm) occur on substitution of ) -H s. Cadmium alkyls seem to show a similar behavior, but for silyl mercury compounds, replacements at both a and P positions result in deshielding. ... 

The first observation of the effect of stereoisomerism on kinetics in the electrochemical reduction of organic compounds was made in 1928 by Herasymenko [2], who found a difference in the behavior of maleic and fumaric acids at the dropping mercury electrode. This pair of geometrical isomers, which are distinguished by fairly rigidly fixed orientation ... 

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