The early light-inducible proteins (ELLPs) in chloroplasts possess a high s
equence homology with the chlorophyll a/b-binding proteins but differ from
those proteins by their substoichiometric and transient appearance. In the
present study ELIPs of pea were isolated by a two-step purification strateg
y: perfusion chromatography in combination with preparative isoelectric foc
ussing. Two heterogeneous populations of ELIPs were obtained after chromato
graphic separation of solubilized thylakoid membranes using a weak anion ex
change column. One of these populations contained ELIPs in a free form prov
iding the first isolation of these proteins. To prove whether the isolated
and pure forms of ELIP bind pigments, spectroscopic and chromatographic ana
lysis were performed. Absorption spectra and TLC revealed the presence of c
hlorophyll a and lutein. Measurements of steady-state fluorescence emission
spectra at 77 K exhibited a major peak at 674 Mm typical for chlorophyll c
t bound to the protein matrix. The action spectrum of the fluorescence emis
sion measured at 674 nm showed several peaks originating mainly from chloro
phyll a. It is proposed that ELIPs are transient chlorophyll-binding protei
ns not involved in light-harvesting but functioning as scavengers for chlor
ophyll molecules during turnover of pigment binding proteins.