The H/D sensitivity of the frequency of the O—O stretching
mode in the resonance Raman spectra of Chlamydomonas and
Synechocystis oxyhemoglobins. Spectra shown are (a)
16O2 in H2O, (b)
16O2 in D2O, and (c) the
H2O − D2O difference spectrum for
16O2. The sensitivity of the
νO—O mode to H2O/D2O is seen
in the difference line at 1132/1141 cm−1 for
Chlamydomonas HbO2, and at 1129/1138
cm−1 for Synechocystis HbO2.
The broad line at ≈1205 cm−1 results from the D—O—D
bending vibration of D2O. Also shown, for
Synechocystis oxyHb, are (d)
18O2 in H2O, (e)
18O2 in D2O, and (f) the
H2O − D2O difference spectrum for
18O2, which shows a difference feature at
1061/1076 cm−1.