TY - JOUR
T1 - Towards a new interaction enzyme : coenzyme
AU - Martinez-Julvez, M
AU - Tejero, J
AU - Peregrina, J R
AU - Nogues, I
AU - Frago, S
AU - Gomez-Moreno, C
AU - Medina, M
PY - 2005/4/1
Y1 - 2005/4/1
N2 - Ferredoxin-NADP+ reductase catalyses NADP+ reduction, being specific for NADP(+)/H. To understand coenzyme specificity determinants and coenzyme specificity reversion, mutations at the NADP+/H pyrophosphate binding and of the C-terminal regions have been simultaneously introduced in Anabaena FNR. The T155G/A160T/L263P/Y303S mutant was produced. The mutated enzyme presents similar k(cat) values for NADPH and NADH, around 2.5 times slower than that reported for WT FNR with NADPH. Its K-m, value for NADH decreased 20-fold with regard to WT FNR, whereas the K, for NADPH remains similar. The combined effect is a much higher catalytic efficiency for NAD(+)/H, with a minor decrease of that for NADP+/H. In the mutated enzyme, the specificity for NADPH versus NADH has been decreased from 67,500 times to only 12 times, being unable to discriminate between both coenzymes. Additionally, giving the role stated for the C-terminal Tyr in FNR, its role in the energetics of the FAD binding has been analysed. (c) 2004 Elsevier B.V. All rights reserved.
AB - Ferredoxin-NADP+ reductase catalyses NADP+ reduction, being specific for NADP(+)/H. To understand coenzyme specificity determinants and coenzyme specificity reversion, mutations at the NADP+/H pyrophosphate binding and of the C-terminal regions have been simultaneously introduced in Anabaena FNR. The T155G/A160T/L263P/Y303S mutant was produced. The mutated enzyme presents similar k(cat) values for NADPH and NADH, around 2.5 times slower than that reported for WT FNR with NADPH. Its K-m, value for NADH decreased 20-fold with regard to WT FNR, whereas the K, for NADPH remains similar. The combined effect is a much higher catalytic efficiency for NAD(+)/H, with a minor decrease of that for NADP+/H. In the mutated enzyme, the specificity for NADPH versus NADH has been decreased from 67,500 times to only 12 times, being unable to discriminate between both coenzymes. Additionally, giving the role stated for the C-terminal Tyr in FNR, its role in the energetics of the FAD binding has been analysed. (c) 2004 Elsevier B.V. All rights reserved.
U2 - 10.1016/bpc.2004.12.034
DO - 10.1016/bpc.2004.12.034
M3 - Article
SN - 0301-4622
VL - 115
SP - 219
EP - 224
JO - Biophysical Chemistry
JF - Biophysical Chemistry
IS - 2-3
ER -