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.
Highlights
The inhibition of enzymes is an important topic for controlling biocatalytic processes relevant in medicine, bioanalytics, and agriculture
Copper-based enzyme that is widely used in environmental bioremediation,[20] chemical synthesis,[21] biological bleaching,[22] and in biosensors for the detection of oxidizing agents.[23,24]
Typical inhibitors for this enzyme are several metal chelating ligands, such as diethylenetriaminepentaacetic acid,[25] dithiothreitol (DTT),[26] thioglycolic acid (TGA),[27] oxalic acid,[28] and citric acid.[28]. These inhibitors diminish the activity of laccase in a concentration range of 5 to 20 mm
Summary
The inhibition of enzymes is an important topic for controlling biocatalytic processes relevant in medicine, bioanalytics, and agriculture. Human matrix metalloproteinases (MMPs), such as collagenase, are inhibited by telechelic POx terminated with N,N-dimethyldodecylammonium (DDA) as end groups for use in dental adhesives.[16] The two antibiotics ciprofloxacin and penicillin, which are both enzyme inhibitors, were shown to be active as end groups of POx.[17] POx with a 2,2’iminodiacetate (IDA) end group was previously reported to diminish the activity of HRP as an entropically driven noncompetitive inhibitor.[18] This is remarkable because IDA is not an inhibitor of HRP The interaction of these POx-IDA species with proteins is so strong that they form noncovalent, organosoluble conjugates with the latter.[19]. We show how POx-IDAs inhibit the enzyme laccase and even stabilize this relatively fragile enzyme
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
