Combination of phase information from isomorphous crystal of R-phycoerythrin from Polysiphonia Urceolata

<正> On the basis of two isoraorphous heavy atom derivatives of R-phycoerythrin (R-PE), both new derivatives of R-PE have also been obtained m 0.05mol/L sodium phosphate buffer and (NH4)2SO4 system containing k2PtCl4 (PTC4) and phenyl mercuric hydroxide (PHMH) reagents by soaking native crystal method. Four heavy atom derivatives were used for phase determination. The overall figure of merit for MIR phases increased to <m> = 0.86 after the solvent flattening. The electron density map calculated is good enough for finding and determining the boundaries of whole molecule and subunits.