Effects of chemical modification on enzymatic activities and stabilities

Abstract

The influence of chemical modification on the initial specific activity, residual activity, and deactivation kinetics of various enzymes is analyzed using a series mechanism. This straightforward multistate sequential model presented is consistent with the enzyme deactivation data obtained from different fields. The enzymes are placed in five different categories depending on the effect of chemical modification on initial specific activity and residual activity or stability. Wherever possible, structure-function relationships are described for the enzymes in the different categories. The categorization provides one avenue that leads to further physical insights into enzyme deactivation processes and into the enzyme structure itself.

Chemical modification of cellulase by maleic anhydride and N‐bromosuccinimide for improved detergent stability

“…These hydrophobic groups tend to destabilize the protein structure when exposed to aqueous environment. Maleylation screens these hydrophobic moieties from unfavorable contact with water and hence brings about stabilization (8,9).…”

Catalytic activity and thermostability of dehydrogenase conjugates with cortisol and progesterone

“…The modification results in decrease of the catalytic activity (Figure 5, Table II) and a loss of thermostability (Figure 10, Table IV). The parallel changes of the enzyme activity and stability are often observed in applied enzymology (23).…”

Regulation of Human Carbonic Anhydrase I (hCAI) Activity by Using a Photochromic Inhibitor

“…In biology, enzymatic control is typically achieved through the use of allostery [1] or by covalently modifying the enzyme (by phosphorylation or dephosphorylation, for example). [2] Some of the original attempts to artificially influence the activity of enzymes rely on chemical modifications of the enzyme structure, [3][4][5][6] an approach that is limited by the fact that the regulation is not reversible. The use of light as a stimulus offers a heightened level of control, and photoresponsive compounds would provide the reversibility needed for practical use.…”