title: Lysine residues on ferredoxin-NADP+ reductase from Anabaena sp. PCC 7119 involved in substrate binding.
abstract: Ferredoxin-NADP+ reductase from Anabaena sp. PCC 7119 is chemically modified by pyridoxal 5'-phosphate. The incorporation of 2 +/- 0.3 mol pyridoxal 5'-phosphate/mol ferredoxin-NADP+ reductase inhibited NADPH-cytochrome c reductase activity by up to 95% while 55% of diaphorase activity still remained. Considerable protection against inactivation was afforded by ferredoxin. Chymotryptic cleavage of the modified enzyme was performed, the peptides were separated by high performance liquid chromatography, and the peptides containing pyridoxamine 5'-phosphate were identified by their fluorescence and by their absorbance at 325 nm. Three major labelled peptides were found. Their sequences were comprised of residues 46-54, 231-235 and 289-295. Lys-53 and -294 were the residues which presented the highest degree of modification and seem to be involved in the ferredoxin binding site of ferredoxin-NADP+ reductase from Anabaena sp. PCC 7119.
authors.affiliation: Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Medina
authors.forename: E
authors.initials: E
authors.lastname: Mendez
authors.forename: C
authors.initials: C
authors.lastname: Gomez-Moreno
mesh_terms: D000595:Amino Acid Sequence; D017033:Anabaena / Q000187:drug effects / Q000201:enzymology*; D001665:Binding Sites / Q000187:drug effects; D001894:Borohydrides / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005287:Ferredoxin-NADP Reductase / Q000037:antagonists & inhibitors / Q000737:chemistry*; D008239:Lysine / Q000737:chemistry* / Q000187:drug effects; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D011485:Protein Binding / Q000187:drug effects; D011732:Pyridoxal Phosphate / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D001894:Borohydrides; D011732:Pyridoxal Phosphate; C025364:sodium borohydride; D005287:Ferredoxin-NADP Reductase; D008239:Lysine