Tuning photophysical properties with ancillary ligands in Ru(II) mono-diimine complexes.

The series of complexes [XRu(CO)(L-L)(L')][PF] (X = H, TFA, Cl; L-L = 2,2'-bipyridyl, 1,10-phenanthroline, 5-amino-1,10-phenanthroline and 4,4'-dicarboxylic-2,2'-bipyridyl; L' = 2PPh, Ph PCHPPh PhPCH═CHPPh) have been synthesized from the starting complex K[Ru(CO)(TFA)] (TFA = CFCO) by first reacting with the phosphine ligand, followed by reaction with the L-L and anion exchange with NaPF. In the case of L-L = phenanthroline and L' = 2PPh, the neutral complex Ru(PhP)(CO)(1,10-phenanthroline)( TFA) is also obtained and its solid state structure is reported. Solid state structures are also reported for the cationic complexes where L-L = phenanthroline, L = 2PPh and X = Cl and for L-L = 2,2'-bipyridyl, L = 2PPh and X = H.

Loop dynamics of the extracellular domain of human tissue factor and activation of factor VIIa.

In the crystal structure of the complex between the soluble extracellular domain of tissue factor (sTF) and active-site-inhibited VIIa, residues 91 and 92 in the Pro(79)-Pro(92) loop of sTF interact with the catalytic domain of VIIa. It is not known, however, whether this loop has a role in allosteric activation of VIIa. Time-resolved fluorescence anisotropy measurements of probes covalently bound to sTF mutants E84C and T121C show that binding uninhibited Factor VIIa affects segmental motions in sTF.

Pressure dissociation of integration host factor-DNA complexes reveals flexibility-dependent structural variation at the protein-DNA interface.

E. coli Integration host factor (IHF) condenses the bacterial nucleoid by wrapping DNA. Previously, we showed that DNA flexibility compensates for structural characteristics of the four consensus recognition elements associated with specific binding (Aeling et al.