Detecting rotational disorder in heme proteins: A comparison between resonance Raman spectroscopy, nuclear magnetic resonance, and circular dichroism. (4th May 2021)

• Record Type: Journal Article
• Authors: Sebastiani, Federico; Milazzo, Lisa; Exertier, Cécile; Becucci, Maurizio; Smulevich, Giulietta
• Other Names: Kiefer Wolfgang guestEditor.; Colomban Philippe guestEditor.; Edwards Howell G. M. guestEditor.
• Is Part Of: Journal of Raman spectroscopy. Volume 52:Number 12(2021)
• Page Start: 2536
• Page End: 2549
• Publication Date: 2021-05-04
• Subjects: double heme insertion -- heme isomerism -- heme orientation -- reversed heme -- vinyl orientation; Raman spectroscopy -- Periodicals; 535.846
• DOI: 10.1002/jrs.6105
• Languages: English
• ISSNs: 0377-0486

Abstract

Abstract: In heme proteins, the canonical and reversed conformations result from the rotation of the heme group by 180° about the α, γ‐meso axis in the protein pocket. The coexistence of the two different heme orientations has been observed both in proteins reconstituted with hemin and in some native proteins. The reversal of the heme orientation can also change certain functional properties of heme proteins. Complementing the results from other experimental techniques, like circular dichroism and nuclear magnetic resonance, resonance Raman spectroscopy provides detailed information on the structure of the reversed heme. This allows one to elucidate the effects of the heme rotation on the vibrational spectra of the peripheral substituents, especially the vinyl groups. Furthermore, the combination of resonance Raman spectroscopy on single crystals and solution samples of heme proteins is proposed to be a sensitive tool to detect heme orientational disorder, even in the absence of structural data. Abstract : In heme proteins the canonical and reversed conformations result from the rotation by 180° about the α, γ‐meso axis of the heme group in the protein pocket. This review focuses on the capability and sensitivity of resonance Raman spectroscopy to unravel details of the structure of the reversed heme, elucidating the effects of the heme rotation on the vibrational spectra of the vinyl groups. The discussion is complemented by results from circular dichroism and nuclear magnetic resonance (NMR).