Absorption spectra of a series of FMN analogs (dotted lines) and the
reconstituted lactate oxidase with these analogs (solid lines) in 0.1 M
phosphate buffer (pH 7.0) at room temperature. The peak intensity of
each FMN analog in free solution was normalized as unity. The
numberings of absorbance spectra are based on the order of the redox
midpoint potential of FMN analogs as follows: 1,
8-CN-FMN; 2, 8-Cl-FMN; 3, 8-H-FMN
(norflavin); 4, 8-H,6-CH3-FMN (isoflavin);
5, 8-CH3S-FMN; 6, FMN;
7, 8-(CH3)2N-FMN (roseoflavin);
8, 6-OH-FMN, 9, 6-NH2-FMN;
10, 8-SH-FMN; 11, 8-NH2-FMN;
12, 8-OH-FMN.