The NADP+-binding site of ferredoxin-NADP+ reductase. Sequence of the peptide containing the essential lysine residue.
The flavoprotein ferredoxin-NADP+ reductase is inactivated and loses its ability to bind NADP+ during covalent modification of a lysine by 5-dimethylaminonaphthalene-1-sulfonyl chloride (dansyl chloride) [Zanetti, G. (1976) Biochim. Biophys. Acta 445, 14-24]. The substrate NADP+ gives almost complete protection against inactivation and modification. These observations are extended in this report by the characterization of an octapeptide containing the dansyl-lysine which was isolated by high-performance liquid chromatography from tryptic digests of protein modified with radiolabeled reagent. The amount of this peptide was severely reduced in protein modified in the presence of NADP+. The sequence of the dansyl-peptide, only partially obtained by Edman degradation, was completed by analysis of the fragments resulting from thermolysin digestion of the purified tryptic dansyl-peptide. Thus, the octapeptide containing the essential lysine residue has the following sequence: H2N-Ser-Val-Ser-Leu-Cys-Val-Lys-Arg-COOH. A comparison with corresponding sequences of other known NADP+-dependent dehydrogenases is attempted.
D000595:Amino Acid Sequence; D001665:Binding Sites; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D003619:Dansyl Compounds / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000032:analysis; D005287:Ferredoxin-NADP Reductase; D008239:Lysine / Q000302:isolation & purification*; D009247:NADH, NADPH Oxidoreductases; D009249:NADP; D010455:Peptides / Q000302:isolation & purification*; D013329:Structure-Activity Relationship
D003619:Dansyl Compounds; D004791:Enzyme Inhibitors; D010455:Peptides; D009249:NADP; D005287:Ferredoxin-NADP Reductase; D009247:NADH, NADPH Oxidoreductases; D008239:Lysine