抄録
Many dye probes have been widely used in
morphological fields, but their mechanisms as
probes remain unknown in almost all cases. We
have explored a possible methodology for discussing
the physiological states of the probes bound to
biological macromolecules, and found that factor
analysis (FA), one of the methods of multivariate
analysis, is useful for isolating the absorption
spectrum of a dye probe associated with protein
molecules. As an example of the simplified reaction
system for protein-ligand interactions, bovine serum
albumin (BSA) and bromocresol purple (BCP) were
used, and the basic methodology was developed
using the FA calculations. In principle, there are two
types of data series in standard spectrophotometry:
spectral series obtained with various concentrations
of the protein at constant amounts of the dye probe
(Type-I data), and those obtained with various
concentrations of the dye probe at constant amounts
of the protein (Type-II data). These data types have
different data matrices. The data type depends on
the experimental conditions, but the Type-II data
are more usual than the Type-I data. Therefore, it
is important to confirm the applicability of the FA
calculations to both data types. In this study we
focused on FA calculations using mainly Type-II
data and confirmed the same results as with Type-I
data. Possible application of this methodology to in
vivo observation is also discussed.