Dynamics of bacteriophage R17 probed with a long-lifetime Ru(II) metal-ligand complex.
The metal-ligand complex, [Ru(2,2'-bipyridine)(2)(4,4'-dicarboxy-2,2'-bipyridine)](2+) (RuBDc), was used as a spectroscopic probe for studying macromolecular dynamics. RuBDc is a very photostable probe that possesses favorable photophysical properties including long lifetime, high quantum yield, large Stokes' shift, and highly polarized emission. To further show the usefulness of this luminophore for probing macromolecular dynamics, we examined the intensity and anisotropy decays of RuBDc when conjugated to R17 bacteriophage using frequency-domain fluorometry with a blue light-emitting diode (LED) as the modulated light source. The intensity decays were best fit by a sum of two exponentials, and we obtained a longer mean lifetime at 4 degrees C (<tau> = 491.8 ns) as compared to that at 25 degrees C (<tau> = 435.1 ns). The anisotropy decay data showed a single rotational correlation time, which is typical for a spherical molecule, and the results showed a longer rotational correlation time at 4 degrees C (2,574.9 ns) than at 25 degrees C (2,070.1 ns). The use of RuBDc enabled us to measure the rotational correlation time up to several microseconds. These results indicate that RuBDc has significant potential for studying hydrodynamics of biological macromolecules.
Kim
Myung Sup
MS
Department of Oral Biochemistry and Molecular Biology, School of Dentistry, Pusan National University, Yangsan 626-870, Korea.
Kim
Jae Hui
JH
Son
Beng Whwa
BW
Kang
Jung Sook
JS
D015082:2,2'-Dipyridyl / Q000737:chemistry*; D016880:Anisotropy; D001435:Bacteriophages; D056831:Coordination Complexes; D008024:Ligands
D056831:Coordination Complexes; D008024:Ligands; D015082:2,2'-Dipyridyl