title: Mechanostability of the Single-Electron-Transfer Complexes of Anabaena Ferredoxin-NADP(+) Reductase.
abstract: The complexes formed between the flavoenzyme ferredoxin-NADP(+) reductase (FNR; NADP(+) =nicotinamide adenine dinucleotide phosphate) and its redox protein partners, ferredoxin (Fd) and flavodoxin (Fld), have been analysed by using dynamic force spectroscopy through AFM. A strategy is developed to immobilise proteins on a substrate and AFM tip to optimise the recognition ability. The differences in the recognition efficiency regarding a random attachment procedure, together with nanomechanical results, show two binding models for these systems. The interaction of the reductase with the natural electron donor, Fd, is threefold stronger and its lifetime is longer and more specific than that with the substitute under iron-deficient conditions, Fld. The higher bond probability and two possible dissociation pathways in Fld binding to FNR are probably due to the nature of this complex, which is closer to a dynamic ensemble model. This is in contrast with the one-step dissociation kinetics that has been observed and a specific interaction described for the FNR:Fd complex.
authors.affiliation: Laboratorio de Microscopías Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, C/Mariano Esquillor, s/n. Ed. I+D+i, 50018, Zaragoza, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Marcuello
authors.affiliation: Laboratorio de Microscopías Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, C/Mariano Esquillor, s/n. Ed. I+D+i, 50018, Zaragoza, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: de Miguel
authors.affiliation: Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Facultad de Ciencias, C/Pedro Cerbuna, 12, 50009, Zaragoza, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Martínez-Júlvez
authors.affiliation: Laboratorio de Microscopías Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, C/Mariano Esquillor, s/n. Ed. I+D+i, 50018, Zaragoza, Spain.|Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Facultad de Ciencias, C/Pedro Cerbuna, 12, 50009, Zaragoza, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Gómez-Moreno
authors.affiliation: Laboratorio de Microscopías Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, C/Mariano Esquillor, s/n. Ed. I+D+i, 50018, Zaragoza, Spain. aglostao@unizar.es.|Fundación ARAID, C/María de Luna, 11. Ed. CEEI Aragón, 50018, Zaragoza, Spain. aglostao@unizar.es.
authors.forename: Anabel
authors.initials: A
authors.lastname: Lostao
mesh_terms: D017033:Anabaena / Q000201:enzymology*; D004579:Electron Transport; D005287:Ferredoxin-NADP Reductase / Q000378:metabolism*; D007700:Kinetics
chemical_list: D005287:Ferredoxin-NADP Reductase
keywords: electron transfer; molecular recognition; proteins; redox chemistry; scanning probe microscopy