Anti‐ferromagnetic exchange in beef adrenodoxin as measured by resonance raman spectroscopy

Adar, Fran; Blum, Haywood; Leigh, John S.; Ohnishi, Tomo̧ko; Salerno, John C.

doi:10.1016/0014-5793(77)80690-x

Cited by 10 publications

(4 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We could observe only two Raman lines at 346 and 380 cm'1 in the lower frequency region spectrum of the cholesterol-free form except for the lines from glycerol (Figure 4). Since oxidized adrenodoxin itself has Raman lines at 289, 346, and 391 cm'1 with almost the same intensities as each other at this excitation wavelength (M. Tsubaki, unpublished observation; Adar et al, 1977), the major part of Raman intensities at 348 cm"1 in the lower spectrum in Figure 4 is expected to be due to adrenodoxin assuming that the oxidized adrenodoxin in both the free and bound state has the same intensity ratios at 289, 346, and 391 cm'1. Cytochrome P-450sa:-cholesterol-adre- Other conditions are the same as in Figure 3.…”

Section: Resultsmentioning

confidence: 93%

Effects of cholesterol and adrenodoxin binding on the heme moiety of cytochrome P-450scc: a resonance Raman study

Tsubaki¹,

Hiwatashi²,

Ichikawa³

1986

Biochemistry

View full text Add to dashboard Cite

The effects of cholesterol and adrenodoxin binding on resonance Raman spectra of cytochrome P-450scc in both oxidized and CO-reduced states were examined. Upon cholesterol binding, oxidized cytochrome P-450scc showed a significant shift of spin equilibrium from low-spin to high-spin state. Addition of adrenodoxin caused a complete conversion of cholesterol-bound oxidized cytochrome P-450scc to a pure high-spin state that was considered to be in the hexacoordinated state judged by the v10 mode at 1620 cm-1 and v3 mode around 1485 cm-1. Cholesterol in substrate binding site may oppose a linear and perpendicular binding of carbon monoxide to the reduced heme iron, leading to the distorted Fe-C-O linkage. This is based on the following observations: (1) an increase of the Fe-CO stretching frequency to 483 from 477 cm-1 upon addition of cholesterol; (2) an enhanced photodissociability of bound carbon monoxide of CO complex of cytochrome P-450scc in the presence of cholesterol. As another aspect of the effect of cholesterol on the CO complex form of cytochrome P-450scc, the enhanced stability of the native form ("P-450" form) was observed. There was no additional effect of reduced adrenodoxin on the Raman spectra of the CO-reduced form of cytochrome P-450scc.

show abstract

Section: Resultsmentioning

confidence: 93%

Effects of cholesterol and adrenodoxin binding on the heme moiety of cytochrome P-450scc: a resonance Raman study

Tsubaki¹,

Hiwatashi²,

Ichikawa³

1986

Biochemistry

View full text Add to dashboard Cite

show abstract

“…A correlation of the peaks in these two spectra shows that, for every FAD peak, there is a corresponding peak in the xanthine oxidase spectrum (Table I). The Raman spectrum of deflavo xanthine oxidase spectra of other Fe2S2 proteins, putidaredoxin, spinach ferredoxin, and adrenodoxin (Tang et al, 1973;Yamamoto, 1974;Adar et al, 1977;Blum et al, 1977;Champion et al, 1978;Yachandra et al, 1983). The frequencies of these three peaks most closely match those of the Fe2S2(Cys)4 group from adrenodoxin.…”

Section: Discussionmentioning

confidence: 84%

Resonance Raman studies of the flavin and iron-sulfur centers of milk xanthine oxidase

Willis¹,

Loehr²

1985

Biochemistry

View full text Add to dashboard Cite

Resonance Raman spectroscopy has been used to study milk xanthine oxidase, an enzyme containing molybdenum, binuclear iron-sulfur clusters, and FAD as cofactors. The contribution of FAD dominates the resonance Raman spectrum at frequencies above 500 cm-1. As expected, no bands assignable to FAD are observed in deflavo xanthine oxidase. The resonance Raman spectrum below 500 cm-1 reveals the contribution of the Fe2S2(Cys)4 groups with frequencies similar to those of adrenodoxin and putidaredoxin. Resonance enhancement profiles of the Fe2S2(Cys)4 clusters indicate intensity variations among the Fe2S2(Cys)4 peaks that are attributed to different excitation wavelength maxima of their bridging and terminal iron-sulfur vibrations. No evidence for Mo-ligand vibrations could be obtained by using excitation wavelengths between 363.8 and 514.5 nm.

show abstract

“…Enzymol. 1986, 24, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. following the procedure of Bax.22 The time proportional phase increment, TPPI, method was used to obtain the absolute phase.23 A mixing time of 100 ms, 48 cycles of the MLEV17 sequence, with a spin-locking field of 10 kHz was employed.…”

Section: Methodsmentioning

confidence: 99%

“…Two naturally occurring opiate-active peptides with the phenylalanine at the third position are dermorphin (Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser)1 23 456789101112and ß-casomorphin (Tyr-Pro-Phe-Pro-Gly-Pro-Ile).4,5 Dermorphin and many related analogues have been conformationally examined both experimentally and theoretically. 6,7 Recently, Schiller and co-workers reported the synthesis of a series of cyclic analogues of dermorphin.8,9 Many of the constrained analogues displayed a high selectivity for the µ-opioid receptor. The conformational analysis of these cyclic analogues of dermorphin has been undertaken.10,11…”

mentioning

confidence: 99%

Configurations of morphiceptins by proton and carbon-13 NMR spectroscopy

Goodman¹,

Mierke²

1989

J. Am. Chem. Soc.

View full text Add to dashboard Cite

As part of our program to study the structure-activity relationship of peptide opioids, we have undertaken the spectroscopic examination of two proline-containing peptides: morphiceptin, Tyr-Pro-Phe-Pro-NHj, and a highly selective morphiceptin analogue, Tyr-Pro-(NMe)Phe-D-Pro-NH2[(NMe)Phe], Using high-resolution *H and 13C NMR experiments, we have assigned two of the four discernible configurational isomers observed for both morphiceptin and the (NMe)Phe analogue. The largest isomer amounting to 55% for morphiceptin and 65% for the (NMe)Phe analogue has been assigned as the all-trans isomer. The second configurational isomer accounting for 25% in both molecules studied adopts a cis conformation about the Tyr-Pro amide bond. The other isomers could not be unambiguously assigned since they are present in small amounts with overlapping and poorly resolved resonances. The exchange between the two major configurational isomers, cis/trans isomerization about the Tyr-Pro amide bond, proved to be extremely slow as established by chemical exchange measurements.Despite the two proline residues, the linear tetrapeptides do not exhibit clear conformational preferences. The measured NOE's, involving intraresidue or interresidue backbone atoms, are indicative of conformational averaging. The experimental examination of these morphiceptins is the first step in the development of structure-activity relationship for these molecules.

show abstract

Anti‐ferromagnetic exchange in beef adrenodoxin as measured by resonance raman spectroscopy

Cited by 10 publications

References 9 publications

Effects of cholesterol and adrenodoxin binding on the heme moiety of cytochrome P-450scc: a resonance Raman study

Effects of cholesterol and adrenodoxin binding on the heme moiety of cytochrome P-450scc: a resonance Raman study

Resonance Raman studies of the flavin and iron-sulfur centers of milk xanthine oxidase

Configurations of morphiceptins by proton and carbon-13 NMR spectroscopy

Contact Info

Product

Resources

About