Phycobilisomes,the light-harvesting antennas in cyanobacteria and red algae,consist of an allophycocyanin core that is attached to the membrane via a core-membrane linker,LCM,and rods comprised of phycocyanin and often also phycoerythrin or phycoerythrocyanin.We have previously reported construction of a water-soluble loop-modified mutant,ApcE(1-240/Δ77-153),of phycobilisome core-membrane linker (give ref).