Isolation and properties of a ferredoxin from leaves of Sambucus racemosa L.

Abstract

Ferredoxin was isolated in good yield from leaves of S. racemosa L. by the following procedure: homogenization in buffered acetone-water (1:1 vol/vol), ion-exchange chromatography on several columns of DEAE-cellulose and purification by gel filtration with Sephadex G-75. The UV and visible spectrum showed maxima at 277, 331, 423 and 466 nm. The EPR spectrum was centered around g = 1.957. The protein sustained an initial photoreduction rate of 86 .mu.mol NADP/mg chlorophyll per h. The amino acid composition was Lys5, His2, Arg1, Asx11, Thr5, Ser7, Glx17, Pro6, Gly7, Ala6-7, Cys4, Val8, Ile5, Leu7, Tyr3, Phe2 and Trp1. The molecule had a MW of 10,700 and contained 2 atoms of Fe. The amino-terminal residue was alanine. These properties are highly similar to those of other angiosperm ferredoxins, Sambucus ferredoxin was found to be most closely related to that of Leucaena.