Crystallization of C-phycocyanin from the marine blue-green alga Agmenellum quadruplicatum.

摘要: The biliprotein photoreceptor, C-phycocyanin, from the blue-green alga Agmenellum quadruplicatum, was crystallized ammonium sulfate solutions using microdiffusion cells. prismatic crystals belong to trigonal space group P321 with unit cell dimensions, a=b=184·5 A, c=60·5 A and γ=120°. Density measurements of these indicate that contains 36 (αβ) units. sublattice feature associated low-order hk0 X-ray reflections intensity distribution along h00 lattice row suggests units are probably aggregated into three (αβ)12 entities per cell. symmetry size suggest C-phycocyanin oligomers possess 32 molecular restrict their approximate dimensions a disk 106·5 in diameter 60°5 thickness. There is striking resemblance between resulting crystal packing association similar proposed models phycobilisomes.