We detected three ferredoxin components, a, b, and c, in green shoots
of Japanese radish seedlings by hydrophobic HPLC analysis using a phen
yl-5PW column. All components were also present in mature leaves. Comp
onent a was further separated into two components, a(1) and a(2), by r
eversed-phase HPLC after carboxymethylation. The existence of four fer
redoxins in the photosynthetic tissue of a single plant species is rep
orted here for the first time. Each individual ferredoxin component wa
s isolated, and its primary structure was analyzed for comparison with
the two leaf ferredoxins, L-Fds A and B, isolated by Wada et al. (J.
Biochem. 105, 619-625 (1989)). The primary structures of components a(
1), a(2), and b were all found in 12 possible structures of L-Fd A ded
ucible from its microheterogeneities. This led us to conclude that L-F
d A is a mixture of three ferredoxins corresponding to components a(1)
, a(2), and b. The complete primary structure of component c was estab
lished by sequencing of the whole protein and of peptides generated by
protease digestion. The N-terminal structure of component c was ident
ical with L-Fd B up to the 11th amino acid residue, suggesting that th
is component is the same ferredoxin as L-Fd B. (C) 1995 Academic Press
, Inc.