TY - JOUR A1 - Jin, Wen A1 - Bernhardt, Rita A1 - Stöcklein, Walter F. M. A1 - Scheller, Frieder W. T1 - Direct electron transfer of adrenodoxin-a [2Fe-2S] protein-- and its mutants on modified gold electrode Y1 - 1998 ER - TY - JOUR A1 - Jetzschmann, Katharina J. A1 - Yarman, Aysu A1 - Rustam, L. A1 - Kielb, P. A1 - Urlacher, V. B. A1 - Fischer, A. A1 - Weidinger, I. M. A1 - Wollenberger, Ulla A1 - Scheller, Frieder W. T1 - Molecular LEGO by domain-imprinting of cytochrome P450 BM3 JF - Colloids and surfaces : an international journal devoted to fundamental and applied research on colloid and interfacial phenomena in relation to systems of biological origin ; B, Biointerfaces N2 - Hypothesis: Electrosynthesis of the MIP nano-film after binding of the separated domains or holocytochrome BM3 via an engineered anchor should result in domain-specific cavities in the polymer layer. Experiments: Both the two domains and the holo P450 BM3 have been bound prior polymer deposition via a N-terminal engineered his6-anchor to the electrode surface. Each step of MIP preparation was characterized by cyclic voltammetry of the redox-marker ferricyanide. Rebinding after template removal was evaluated by quantifying the suppression of the diffusive permeability of the signal for ferricyanide and by the NADH-dependent reduction of cytochrome c by the reductase domain (BMR). Findings: The working hypothesis is verified by the discrimination of the two domains by the respective MIPs: The holoenzyme P450 BM3 was ca. 5.5 times more effectively recognized by the film imprinted with the oxidase domain (BMO) as compared to the BMR-MIP or the non-imprinted polymer (NIP). Obviously, a cavity is formed during the imprinting process around the hiss-tag-anchored BMR which cannot accommodate the broader BMO or the P450 BM3. The affinity of the MIP towards P450 BM3 is comparable with that to the monomer in solution. The hiss-tagged P450 BM3 binds (30 percent) stronger which shows the additive effect of the interaction with the MIP and the binding to the electrode. KW - Molecularly imprinted polymers KW - Protein imprinting KW - Electropolymerization KW - Cytochrome P450 Y1 - 2018 U6 - https://doi.org/10.1016/j.colsurfb.2018.01.047 SN - 0927-7765 SN - 1873-4367 VL - 164 SP - 240 EP - 246 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Jetzschmann, Katharina J. A1 - Tank, Steffen A1 - Jagerszki, Gyula A1 - Gyurcsanyi, Robert E. A1 - Wollenberger, Ulla A1 - Scheller, Frieder W. T1 - Bio-Electrosynthesis of Vectorially Imprinted Polymer Nanofilms for Cytochrome P450cam JF - ChemElectroChem N2 - A new approach for synthesizing a vectorially imprinted polymer (VIP) is presented for the microbial cytochrome P450cam enzyme. A surface attached binding motif of a natural reaction partner of the target protein, putidaredoxin (Pdx), is the anchor to the underlying transducer. The 15 amino acid peptide anchor, which stems from the largest continuous amino acid chain within the binding site of Pdx was modified: (i) internal cysteines were replaced by serines to prevent disulfide bond formation; (ii) 2 ethylene glycol units were attached to the N-terminus as a spacer region; and (iii) an N-terminal cysteine was added to allow the immobilization on the gold electrode surface. Immobilization on GCE was achieved via an N-(1-pyrenyl)maleimide (NPM) cross-linker. In this way oriented immobilization of P450cam was accomplished by binding it to a peptide-modified gold or glassy carbon electrode (GCE) prior to the electrosynthesis of a polymer nanofilm around the immobilized target. This VIP nanofilm enabled reversible oriented docking of P450cam as it is indicated by the catalytic oxygen reduction via direct electron transfer between the enzyme and the underlying electrode. Catalysis of oxygen reduction by P450cam bound to the VIP-modified GCE was used to measure rebinding to the VIP. The mild coupling of an oxidoreductase with the electrode may be appropriate for realizing electrode-driven substrate conversion by instable P450 enzymes without the need of NADPH co-factor. KW - cytochrome P450 KW - direct electron transfer KW - electropolymerization KW - molecularly imprinted polymers KW - protein imprinting Y1 - 2019 U6 - https://doi.org/10.1002/celc.201801851 SN - 2196-0216 VL - 6 IS - 6 SP - 1818 EP - 1823 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Jetzschmann, Katharina J. A1 - Jagerszki, Gyula A1 - Dechtrirat, Decha A1 - Yarman, Aysu A1 - Gajovic-Eichelmann, Nenad A1 - Gilsing, Hans-Detlev A1 - Schulz, Burkhard A1 - Gyurcsanyi, Robert E. A1 - Scheller, Frieder W. T1 - Vectorially Imprinted Hybrid Nanofilm for Acetylcholinesterase Recognition JF - Advanced functional materials N2 - Effective recognition of enzymatically active tetrameric acetylcholinesterase (AChE) is accomplished by a hybrid nanofilm composed of a propidium-terminated self-assembled monolayer (Prop-SAM) which binds AChE via its peripheral anionic site (PAS) and an ultrathin electrosynthesized molecularly imprinted polymer (MIP) cover layer of a novel carboxylate-modified derivative of 3,4-propylenedioxythiophene. The rebinding of the AChE to the MIP/Prop-SAM nanofilm covered electrode is detected by measuring in situ the enzymatic activity. The oxidative current of the released thiocholine is dependent on the AChE concentration from approximate to 0.04 x 10(-6) to 0.4 x 10(-6)m. An imprinting factor of 9.9 is obtained for the hybrid MIP, which is among the best values reported for protein imprinting. The dissociation constant characterizing the strength of the MIP-AChE binding is 4.2 x 10(-7)m indicating the dominant role of the PAS-Prop-SAM interaction, while the benefit of the MIP nanofilm covering the Prop-SAM layer is the effective suppression of the cross-reactivity toward competing proteins as compared with the Prop-SAM. The threefold selectivity gain provided by i) the shape-specific MIP filter, ii) the propidium-SAM, iii) signal generation only by the AChE bound to the nanofilm shows promise for assessing AChE activity levels in cerebrospinal fluid. KW - acetylcholinesterase KW - biomimetic sensors KW - molecularly imprinted electropolymers KW - peripheral anionic site KW - propidium Y1 - 2015 U6 - https://doi.org/10.1002/adfm.201501900 SN - 1616-301X SN - 1616-3028 VL - 25 IS - 32 SP - 5178 EP - 5183 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Iliev, I. A1 - Kaisheva, A. A1 - Scheller, Frieder W. A1 - Pfeiffer, Dorothea T1 - Amperometric gas-diffusion / enzyme electrode Y1 - 1995 ER - TY - JOUR A1 - Ignatov, S. A1 - Shishniashvili, D. A1 - Ge, Bixia A1 - Scheller, Frieder W. A1 - Lisdat, Fred T1 - Amperometric biosensor based on a functionalized gold electrode for the detection of antioxidants Y1 - 2002 ER - TY - JOUR A1 - Ignatov, S. A1 - Ge, Bixia A1 - Scheller, Frieder W. A1 - Lisdat, Fred T1 - Detection of the antioxidant activity detection of flavonoids by using superoxide sensor Y1 - 2001 SN - 1-58603-164-3 ER - TY - JOUR A1 - Huang, T. A1 - Warsinke, Axel A1 - Kuwana, T. A1 - Scheller, Frieder W. T1 - The determination of L-phenylalanine based on a novel NADH-detecting biosensor Y1 - 1998 ER - TY - JOUR A1 - Huang, T. A1 - Warsinke, Axel A1 - Koroljova-Skorobogatko, O. V. A1 - Makower, Alexander A1 - Kuwana, T. A1 - Scheller, Frieder W. T1 - A bienzyme carbon paste electrode for the sensitive detection of NADPH and the measurement of glucose-6- phosphate dehydrogenase Y1 - 1999 ER - TY - JOUR A1 - Hock, Bertold A1 - Scheller, Frieder W. T1 - Conclusions and outlook Y1 - 2001 ER -