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Surface enhanced resonance Raman scattering as a probe of the spin state of structurally related cytochromes P‐450 from rat liver
Author(s) -
Kelly K.,
Rospendowski B.N.,
Smith W.E.,
Wolf C.R.
Publication year - 1987
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(87)80203-x
Subject(s) - chemistry , spin (aerodynamics) , resonance (particle physics) , raman scattering , site directed spin labeling , raman spectroscopy , spin states , denaturation (fissile materials) , analytical chemistry (journal) , electron paramagnetic resonance , spin label , crystallography , colloid , nuclear magnetic resonance , inorganic chemistry , nuclear chemistry , atomic physics , organic chemistry , biochemistry , optics , physics , membrane , engineering , aerospace engineering
Surface enhanced resonance Raman scattering (SERRS) was observed from structurally related drug‐induced rat liver cytochromes P‐450 adsorbed on a silver colloid. Careful control of pH and the sequence of addition of components to the sol is required to prevent protein denaturation at the surface due to conversion to P‐450's biologically inactive form P‐420 or haem loss. A low‐spin P‐450 (PB 3a ), a mixed low‐and high‐spin P‐450 (PB 3b ) and a predominantly high‐spin P‐450 (MC 1a ) were investigated. Spectra recorded in the 1300–1700 cm −1 frequency region, containing the oxidation state marker ν 4 at 1375 cm −1 (Fe 3+ ) and spin state markers ν 10 (1625 cm −1 , high‐spin; 1633 cm −1 , low‐spin) and ν 19 (1575 cm −1 , high‐spin; 1585 cm −1 , low‐spin) were used to differentiate between the spin states of the various forms of cytochrome P‐450. As well as the established spin state marker bands, the intensity of a band at 1400 cm −1 appeared to depend on the high‐spin content. Thus, with this method SERRS from silver colloids can be used to determine spin states of related cytochromes P‐450 in dilute solution (10 −8 M) and may be of value in studies of protein‐substrate interactions.