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Measurement of Heme Synthesis Levels in Mammalian Cells
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Measurement of Heme Synthesis Levels in Mammalian Cells

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Coupling of the heme and an internal disulfide bond in human neuroglobin

Djemel Hamdane1, Laurent Kiger, Sylvia Dewilde

  • 1Inserm U473, 84 rue du General Leclerc, 94276 Le Kremlin-Bicêtre, Cedex France.

Micron (Oxford, England : 1993)
|March 24, 2004
PubMed

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Protein Modifications in the RER

Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
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Spin–Spin Coupling: One-Bond Coupling

Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
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¹H NMR: Long-Range Coupling

The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
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