Table 1. Optical Properties of Various Wild-Type rTHB1 Complexes at pH 7.1.

protein state	Soret maximum (nm)	α (nm)	β (nm)	CTa (nm)	ε at Soret maximum (mM–1 cm–1)
Fe(III) (pH 4.8)	408	503, 542 (sh)		630	144
Fe(III) (pH 7.1)	410	536, 568 (sh)		630 (sh)	125
Fe(III) (pH 10.8)	412	538, 570 (sh)			118
Fe(II)	426	529	559		195
Fe(III)–CN–	417	546			104
Fe(II)–CN–	432	534	564		187
Fe(III)–NO	421	535	570		136
Fe(II)–NO	418	548	573		133
Fe(II)–O2	412	545	581		119
Fe(II)–CO	421	541	564		226

^aCharge transfer band.