5666-16-0Relevant articles and documents
Ghisla et al.
, p. 589,590, 592 (1974)
Not as easy as π: An insertional residue does not explain the π-helix gain-of-function in two-component FMN reductases
McFarlane, Jeffrey S.,Hagen, Richard A.,Chilton, Annemarie S.,Forbes, Dianna L.,Lamb, Audrey L.,Ellis, Holly R.
, p. 123 - 134 (2018/11/23)
The π-helix located at the tetramer interface of two-component FMN-dependent reductases contributes to the structural divergence from canonical FMN-bound reductases within the NADPH:FMN reductase family. The π-helix in the SsuE FMN-dependent reductase of the alkanesulfonate monooxygenase system has been proposed to be generated by the insertion of a Tyr residue in the conserved α4-helix. Variants of Tyr118 were generated, and their X-ray crystal structures determined, to evaluate how these alterations affect the structural integrity of the π-helix. The structure of the Y118A SsuE π-helix was converted to an α-helix, similar to the FMN-bound members of the NADPH:FMN reductase family. Although the π-helix was altered, the FMN binding region remained unchanged. Conversely, deletion of Tyr118 disrupted the secondary structural properties of the π-helix, generating a random coil region in the middle of helix 4. Both the Y118A and Δ118 SsuE SsuE variants crystallize as a dimer. The MsuE FMN reductase involved in the desulfonation of methanesulfonates is structurally similar to SsuE, but the π-helix contains a His insertional residue. Exchanging the π-helix insertional residue of each enzyme did not result in equivalent kinetic properties. Structure-based sequence analysis further demonstrated the presence of a similar Tyr residue in an FMN-bound reductase in the NADPH:FMN reductase family that is not sufficient to generate a π-helix. Results from the structural and functional studies of the FMN-dependent reductases suggest that the insertional residue alone is not solely responsible for generating the π-helix, and additional structural adaptions occur to provide the altered gain of function.
Catalytic reduction of redox-active co-factors and proteins by dihydrogen with Sephadex supported platinum clusters as catalysts
Bhaduri, Sumit,Sharma, Krishna
, p. 207 - 208 (2007/10/03)
The platinum carbonyl cluster [Pt15(CO)30]2-, anchored onto QAE-SEPHADEX anion exchanger, is an effective catalyst for the reduction of flavin co-factors, lipoamide dehydrogenase and CytCox.
