1313861-39-0Relevant articles and documents
Chalcogenide substitution in the [2Fe] cluster of [FeFe]-hydrogenases conserves high enzymatic activity
Kertess,Wittkamp,Sommer,Esselborn,Rüdiger,Reijerse,Hofmann,Lubitz,Winkler,Happe,Apfel
, p. 16947 - 16958 (2017)
[FeFe]-Hydrogenases efficiently catalyze the uptake and evolution of H2 due to the presence of an inorganic [6Fe-6S]-cofactor (H-cluster). This cofactor is comprised of a [4Fe-4S] cluster coupled to a unique [2Fe] cluster where the catalytic turnover of H2/H+ takes place. We herein report on the synthesis of a selenium substituted [2Fe] cluster [Fe2{μ(SeCH2)2NH}(CO)4(CN)2]2- (ADSe) and its successful in vitro integration into the native protein scaffold of [FeFe]-hydrogenases HydA1 from Chlamydomonas reinhardtii and CpI from Clostridium pasteurianum yielding fully active enzymes (HydA1-ADSe and CpI-ADSe). FT-IR spectroscopy and X-ray structure analysis confirmed the presence of structurally intact ADSe at the active site. Electrochemical assays reveal that the selenium containing enzymes are more biased towards hydrogen production than their native counterparts. In contrast to previous chalcogenide exchange studies, the S to Se exchange herein is not based on a simple reconstitution approach using ionic cluster constituents but on the in vitro maturation with a pre-synthesized selenium-containing [2Fe] mimic. The combination of biological and chemical methods allowed for the creation of a novel [FeFe]-hydrogenase with a [2Fe2Se]-active site which confers individual catalytic features.
Synthesis and characterization of single, double, and triple butterfly [2Fe2E] (E = Se, S) cluster complexes related to the active site of [FeFe]-hydrogenases
Gao, Wei,Song, Li-Cheng,Yin, Bang-Shao,Zan, Hui-Ning,Wang, De-Fu,Song, Hai-Bin
, p. 4097 - 4107 (2011/10/03)
As the active site mimics of [FeFe]-hydrogenases, 14 new butterfly [2Fe2E] (E = Se, S) cluster complexes have been prepared by various synthetic routes. The N-substituted single-butterfly [2Fe2Se] complexes [(μ-SeCH 2)2NC(O)R]Fe2(CO)6 (1, R = Me; 2, R = Ph; 3, R = PhCH2O) were prepared by reactions of the in situ formed (μ-LiSe)2Fe2(CO)6 with RC(O)N(CH 2Cl)2, whereas the corresponding [2Fe2S] complexes [(μ-SCH2)2NC6H4R-p]Fe 2(CO)6 (4, R = CO2Et; 5, R = CH2OH) were produced by reaction of the in situ generated (μ-HS)2Fe 2(CO)6 with aqueous CH2O followed by treatment with p-RC6H4NH2. The parent single-butterfly [2Fe2Se] complex [(μ-SeCH2)2NH]Fe2(CO) 6 (6) could be prepared by reaction of the N-substituted complex 3 with deprotecting reagent BBr3, BF3·OEt 2/EtSH, or BF3·OEt2/Me2S, whereas the N-substituted single-butterfly [2Fe2Se] complexes [(μ-SeCH 2)2NC(O)R]Fe2(CO)6 (7, R = Et; 8, R = PhCH2) were produced by reactions of 6 with acylating agents RC(O)Cl in the presence of Et3N. While the known parent single-butterfly [2Fe2S] complex [(μ-SCH2)2NH]Fe 2(CO)6 reacted with 2,6-[ClC(O)]2C 5H3N to afford double-butterfly [2Fe2S] complex [Fe 2(CO)6(μ-SCH2)2NC(O)] 2(2,6-C5H3N) (9), the new N-hydroxyethyl- substituted single-butterfly [2Fe2Se] complex [(μ-SeCH2) 2N(CH2)2OH]Fe2(CO)6 (10) could be obtained by the in situ reaction of (μ-HSe)2Fe 2(CO)6 with (HOCH2)2N(CH 2)2OH. Interestingly, complex 10 could react with [ClC(O)]2CH2 or 1,3,5-[ClC(O)]3C 6H3 in the presence of Et3N to give the corresponding double-butterfly [2Fe2Se] complex [Fe2(CO) 6(μ-SeCH2)2N(CH2) 2O2C]2CH2 (11) and triple-butterfly complex [Fe2(CO)6(μ-SeCH2) 2N(CH2)2O2C]3(1,3,5- C6H3) (12), whereas the known single-butterfly [2Fe2S] complex [(μ-SCH2)2N(CH2)2OH] Fe2(CO)6 could react with 2,6-[ClC(O)]2C 5H3N and 1,3,5-[ClC(O)]3C6H 3 in the presence of Et3N to afford the corresponding double-butterfly [2Fe2S] complex [Fe2(CO)6(μ-SCH 2)2N(CH2)2O2C] 2(2,6-C5H3N) (13) and triple-butterfly complex [Fe2(CO)6(μ-SCH2)2N(CH 2)2O2C]3(1,3,5-C6H 3) (14), respectively. All the new complexes 1-14 have been characterized by elemental analysis and spectroscopy, as well as by X-ray crystallography for 1-4, 7-9, and 14. In addition, the electrochemical study indicated that complexes 1 and 2 can catalyze the proton reduction of HOAc to give hydrogen.
