Abstract:Ferredoxin-NADP+ reductase (FNR) catalyzes the reduction of NADP+ to NADPH in an overall reversible reaction, showing some differences in the mechanisms between cyanobacterial and higher plant FNRs. During hydride transfer it is proposed that the FNR C-terminal Tyr is displaced by the nicotinamide. Thus, this C-terminal Tyr might be involved not only in modulating the flavin redox properties, as already shown, but also in nicotinamide binding and hydride transfer. FNR variants from the cyanobacterium Anabaena … Show more
“…6 with 3A and 3C). These observations correlated with the changes produced in the FNR spectrum upon NADP + complexation (Tejero et al, 2005). Despite the presence of NADP + barely affected apparent k BC between Fld and FNR (Table 1, Fig.…”
Section: Kinetic Analysis Of Multiple-wavelength Absorption Datasupporting
“…6 with 3A and 3C). These observations correlated with the changes produced in the FNR spectrum upon NADP + complexation (Tejero et al, 2005). Despite the presence of NADP + barely affected apparent k BC between Fld and FNR (Table 1, Fig.…”
Section: Kinetic Analysis Of Multiple-wavelength Absorption Datasupporting
“…Compared to the plant-type FNRs, an equivalent substitution affected the enzymatic activity differently (Table 3). For Anabaena FNR, the replacement of the C-terminal Tyr by Ser led to a considerable decrease in k cat for the diaphorase activity, 26 but the equivalent replacement of C. tepidum FNR did not affect the kinetic parameters significantly. Interactions of the different FNR variants with NADP + were analyzed by difference spectroscopy (Fig.…”
Section: Resultsmentioning
confidence: 93%
“…Although the peak in the 500-510 nm region in the difference spectra has been reported as an indication of stacking between the NADP + nicotinamide ring and the isoalloxazine ring of FAD in the plant-type FNRs, we did not obtain any evidence of such stacking in the case of TrxRlike FNRs. 26,27 Currently, we can conclude only that NADP + binding modulates the local environment around the FAD molecule.…”
Section: Resultsmentioning
confidence: 99%
“…4,24 In order to elucidate the functional role of this FAD-stacking aromatic residue in C. tepidum FNR, we have introduced point mutations into Phe337, which has been done for pea 25 and Anabaena FNRs. 26 Comparisons of the UV-visible spectrum of the WT enzyme with those of the Phe337Ser, Phe337Tyr and Phe337His variants revealed that replacement of Phe337 in C. tepidum FNR results in small changes in the absorption properties of the flavin prosthetic group (Fig. 5a).…”
“…4: Schematic representation of electron and proton transfer steps catalyzed by the flavoprotein ferredoxin-NADP + -reductase (protein structure PDB-code 2BSA, structural data from ref. [37]). …”
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.