One unit of enzyme activity was defined as 1 [micro]M of hydrolyzed hippuryl-L-phenylalanine per min, using as the molar extinction coefficient
19.4 [cm.sup.-1] [M.sup.-1].
The molar extinction coefficients
of its UV/VIS absorption bands were also determined.
Wavelength absorption (X), oscillator strength (f), the light harvesting efficiency (LHE) and molar extinction coefficient
(e) of D substituted by [C.sub.n][H.sub.2n+1] alkyl chain calculated by TD-B3LYP/6-31G(d,p) in chloroform solvent.
[epsilon]: molar extinction coefficient
, q: fluorescence quantum yield, q/[q.sub.0]: fluorescence quantum yield normalized by the value in water ([q.sub.0]), and [[lambda].sub.bs,max] and [[lambda].sub.fl,max]: wavelengths of maximum of the absorption and fluorescence spectra, respectively.
Addition of a small amount of DMF solution of 1 to water (DMF to water 1: 100 vol.%) resulted in strengthening of the long-wavelength band of the dye (Figure 5(a), curve 7), which cannot be explained by molecular association, since the molar extinction coefficient
did not decrease there.
These observed trends are due in part to molar extinction coefficients
and EI ionization cross-sections considerations, thus reflecting the physics of the detectors being used.
Quantification was based on the molar extinction coefficient
of 6.22m[M.sup.-1] [cm.sup.-1] of NADPH.
The molar extinction coefficient
is the same for fluorescein in solution and fluorescein immobilized on the microspheres.
We thank Linlin Ding for providing [Alpha]crystallin (Jules Stein Eye Institute) and Ray Borkman and Grady Knight (Georgia Institute of Technology) for providing the molar extinction coefficient
Where Iumax is the molar extinction coefficient
(mol-1.L.cm-1) and I is full width at half maximum FWHM (cm-1).
The band at 440 nm of JJ-7 exhibits a molar extinction coefficient
of 4.5 x [10.sup.3] [M.sup.-1] [cm.sup.-1], which is slightly lower than that of N719 dye (5.4 x [10.sup.3] [M.sup.-1] [cm.sup.-1]).
The initial rates were obtained by extrapolation to zero time and the activity computed as nmol [min.sup.-1] mg [protein.sup.-1] using the molar extinction coefficient
of NADPH ([[epsilon].sub.340 nm]) (6.22 x [10.sup.3] [M.sup.-1] [cm.sup.-1]).