Poly(2‐oxazoline)s with a 2,2′‐Iminodiacetate End Group Inhibit and Stabilize Laccase

Abstract

Poly(2‐oxazoline)s (POxs) with 2,2′‐iminodiacetate (IDA) end groups were investigated as inhibitors for laccase. The polymers with the IDA end groups are reversible, competitive inhibitors for this enzyme. The IC50 values were found to be in a range of 1–3 mm. Compared with IDA alone, the activity was increased by a factor of more than 30; thus indicating that attaching a polymer chain to an inhibitor can already improve the activity of the former. The enzyme activity drops to practically zero upon increasing the concentration of the most active telechelic inhibitor, IDA‐PEtOx30‐IDA (PEtOx: poly(2‐ethyl‐2‐oxazoline)), from 5 to 8 mm. This unusual behavior was investigated by means of dynamic light scattering, which showed specific aggregation above 5 mm. Furthermore, the laccase could be stabilized in the presence of POx‐IDA, upon addition at a concentration of 20 mm and higher. Whereas laccase becomes completely inactive at room temperature after one week, the stabilized laccase is fully active for at least a month in aqueous solution.

Full Thermal Switching of Enzymes by Thermoresponsive Poly(2‐oxazoline)‐Based Enzyme Inhibitors

“…[20] Te mperature control of the activity of these enzymes could improvet he biosensors, but might also allow to specifically interact with production cascades to controlt he selective synthesis of fine chemicals. [21,22] Diluting the polymer/enzyme mixtures alwaysr esultsi nf ulla ctivity of the enzyme, indicating that the inhibition is fully reversible. Interestingly,P OX-IDAs are dead-endi nhibitors for both enzymes, that is, they can fully inhibitt he enzyme activity.T his offers the potential of fully switching enzyme activity.P oly(2oxazoline)s have been found to be excellent lower critical solution temperature (LCST)p olymers, which can be adjusted in their cloud-point temperature by copolymerization of different 2-alkyl-oxazolines and by varying the end groups.…”

“…These polymers were also found to be competitive inhibitors for laccase, which can be found in bioremediation, chemical synthesis, wine stabilization, and biosensing . Temperature control of the activity of these enzymes could improve the biosensors, but might also allow to specifically interact with production cascades to control the selective synthesis of fine chemicals . Diluting the polymer/enzyme mixtures always results in full activity of the enzyme, indicating that the inhibition is fully reversible.…”

Inhibition in multicopper oxidases: a critical review

“…The most commonly studied MCO inhibitors are halides and pseudohalides (e.g., azide and cyanide), [26][27][28][29][30][31] but the activity of MCOs is also affected by metal ions (e.g., Ca 2+ , Mn 2+ , Fe 2+/3+ , Co 2+ , Cu +/2+ , Ag + , Zn 2+ , Hg 2+ , Al 3+ and As 3+/5+ ), [32][33][34][35][36][37][38][39][40] reactive oxygen species (ROS) such as O 2− and H 2 O 2 , 41 reducing agents (e.g., L-cysteine, dithiothreitol, 2-mercaptoethanol), 36,[42][43][44] chelating agents (e.g., EDTA), 36,41,44,45 chaotropic agents (e.g., SDS and urea) 32,36,41,45,46 and others (e.g., short alcohols, ionic liquids and polymer end groups). 41,[47][48][49][50] Misleadingly, these enzyme inactivators are routinely surveyed alongside the more specific inhibitors of MCO activity. 32,36,37,41,[44][45][46]51 This review focuses on reversible MCO inhibitors, and does not examine loss of catalytic activity resulting from protein unfolding or loss of Cu cofactors.…”

Design, Synthesis and Bioactivity of Novel Fluoropyrazole Hydrazides

“…同时, 金属离子 [7][8][9][10][11] 、还原剂 [9,[12][13][14] 、螯合剂 [9,14] 及表面 活性剂 [7,9,15] 等也被证明具有漆酶抑制活性. 近年来, 一 些简单有机化合物(如短醇和聚合物末端基团)对漆酶的 抑制活性 [16][17] 成为一个新的研究热点. 本课题组前期发 现的 4-氯肉桂醛缩氨基硫脲(PMDD-5Y)具有良好的生 物活性 [18] , 进一步研究证明该化合物是一种漆酶抑制 剂 [19] .…”