Abstract:

The main chlorophyll a/b light-harvesting complex (LHCⅡ) has been isolated directly from thylakoid membranes of marine green alga (Bryopsis corticulans Setch.) by two consecutive runs of anion exchange and gel-filtration chromatography. LHCⅡ proteins in the membrane extracts treated with 3% n-Octyl-b-D-glucopyranoside (OG) obtained specific binding ability on Q Sepharose column, and thus were isolated from the thylakoid membranes in a highly selective fraction. The monomeric, trimeric and oligomeric subcomplexes of LHCⅡ have been obtained by fractionation of the LHCⅡ mixes with sucrose density gradient ultracentrifugation. The SDS-PAGE analysis of peptide composition and absorption spectrum showed that LHCⅡ monomers, trimers and oligomers prepared through this work were intact and in high purity. Our report is the first to show that it is possible to purify LHCⅡ directly from thylakoid membranes without extensively biochemical purification.

Key words: photosynthesis, light-harvesting complex, purification, high performance liquid chroma-tography