1: Biochim Biophys Acta  1975 May 30;393(1):10-4 

Degree of dissociation of apohemoglobin studied by nano-second
fluorescence-polarization technique.

Kinosita K Jr, Mitaku S, Ikegami A.

A fluorescent dye 1-anilino-8-naphthalene sulfonate was complexed with human
apohemoglobin and sperm whale apomyoglobin. Nanosecond fluorescence-polarization
kinetics were measured for each of these complexes in KC1 solutions to obtain
their fluorescence lifetimes and rotational correlation times. The rotational
correlation time of apohemoglobin-dye complex was found to be 21 ns, which was
about twice that of apomyoglobin-dye complex, 11 ns. These values were constant
over an ionic strength range from 0 to 1.7. Circular dichroism spectra (215-300
nm) and fluorescence lifetimes of the complexes were also found to be
independent of the ionic strength, indicating that no gross conformational
change occurs with the change in the salt concentration, These results suggest
that apohemoglobin remains dimeric over the ionic-strength range examined.

PMID: 1138915 [PubMed - indexed for MEDLINE]