Properties of Common Wheat Ferredoxin, and a Comparison with Ferredoxins from Related Species of Triticum and Aegilops1

Publisher Website
Google Scholar
Abstract
Wheat ferredoxin was purified from the leaves of common wheat (Triticum aestivum). The absorption spectrum showed maxima at 465, 425, 332, and 278 nm. The absorbanci ratio, A425 nm/ A278 nm was 0·49, and the millimolar extinction coefficient at 425 nm was 10·8 mM−1 cm−1. The amino acid composition was determined to be Lys5 His2, Arg1 Asp11, Thr5 Ser7 Glu18 Pro5 Gly6 Ala7 Cys5 Val7 Met1 Ile4 Leu7 Tyr4 Phe1 and Trp1 The total number of amino acid residues was 97. The molecular weight was calculated from the amino acid composition to be 10,829, including iron and sulfur atoms. This value was confirmed by other methods, which were based on the contents of non-heme iron and of terminal amino acid. The N-terminal amino acid was alanine, and the C-terminal amino acid sequence was -Glu Leu-Thr-AlaCOOH. Comparative studies were performed between T. aestivum ferredoxin and ferredoxins isolated from closely related species; these were T. aegilopoides. T. durum, Ae. squarrosa, and Ae. ovata. No significant differences in the properties of these ferredoxins were detected. It was also shown that these ferredoxins are immunologically homologous. It is, therefore, likely that one molecular species of ferredoxin is distributed through two genera of Trilicum and Aegiops.