Oxidized ferredoxin:NADP+ oxidoreductase (FNR) was slowly and irreversibly inactivated by N-ethylmaleimide. Complete protection against inactivation was afforded by saturating concentrations of NADP+. In the presence of NADPH, a rapid inhibition of the enzyme ensued; however, this inhibition was found to be reversible. In the tryptic map of the flavoprotein, modified with N-ethyl[2,3-14C]maleimide in oxidizing conditions, a unique radioactive peptide was found. Its sequence comprised residues 110-117 of the enzyme: Lys116 was shown to be the residue alkylated by N-ethylmaleimide. It is noteworthy that the same residue of FNR was found to be modified by 5-dimethylaminoaphthalene-1-sulfonyl(dansyl) chloride at the putative NADP(H)-binding site [Cidaria, D., Biondi, P. A., Zanetti, G. & Ronchi, S. (1985) Eur. J. Biochem. 146, 295-299]. Furthermore, the data reported here demonstrate that the sulfhydryl groups of FNR are not involved in enzyme inactivation by N-ethylmaleimide.
Identification of Lys116 as the target of N-ethylmaleimide inactivation of ferredoxin:NADP+ oxidoreductase / A. Aliverti, G. Gadda, S. Ronchi, G. Zanetti. - In: EUROPEAN JOURNAL OF BIOCHEMISTRY. - ISSN 0014-2956. - 198:1(1991 May 23), pp. 21-24.
|Titolo:||Identification of Lys116 as the target of N-ethylmaleimide inactivation of ferredoxin:NADP+ oxidoreductase|
ALIVERTI, ALESSANDRO (Primo)
RONCHI, SEVERINO (Penultimo)
ZANETTI, GIULIANA (Ultimo)
|Parole Chiave:||protein ; enzyme ; flavoprotein ; photosynthesis ; bilogical oxidoreduction ; flavin nucleotide ; nicotinamide nucleotide ; enzyme-substrate recognition ; catalytic mechanism ; protein modification ; catalytic mechanism|
|Settore Scientifico Disciplinare:||Settore BIO/10 - Biochimica|
|Data di pubblicazione:||23-mag-1991|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1111/j.1432-1033.1991.tb15981.x|
|Appare nelle tipologie:||01 - Articolo su periodico|