The NADP+-binding site of ferredoxin-NADP+ reductase: sequence of the peptide containing the essential lysine residue

• Published in: European journal of biochemistry Vol. 146; no. 2; pp. 295 - 299
• Main Authors: CIDARIA, D, BIONDI, P. A, ZANETTI, G, RONCHI, S
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell 15.01.1985
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Binding Sites; Biological and medical sciences; Chemical Phenomena; Chemistry; Chromatography, High Pressure Liquid; Dansyl Compounds - pharmacology; Enzyme Inhibitors - analysis; Enzymes and enzyme inhibitors; Ferredoxin-NADP Reductase; Fundamental and applied biological sciences. Psychology; Lysine - isolation & purification; NADH, NADPH Oxidoreductases; NADP; Oxidoreductases; Peptides - isolation & purification; Structure-Activity Relationship; Binding site; Ferredoxin-NADP+ reductase; NADP; Lysine
• ISSN: 0014-2956; 1432-1033
• DOI: 10.1111/j.1432-1033.1985.tb08652.x

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.