Isotopic probe for spectroscopic studies of heme

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Sandhya C. Manjunath (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
Gregory Raner

Abstract: Cytochrome P450 enzymes (P450s) are heme containing monooxygenases with great potential in applications focused in biotechnological areas. An understanding of the precise chemical process behind this enzyme is essential in research in the areas of pharmaceuticals and biochemistry. In order to get a better understanding of P450s, it is important to provide spectroscopic characterization of the electron spin distributions within the heme macrocycle. Paramagnetic NMR has been shown to be a powerful tool for probing electronic distribution and spin-densities within the heme macrocycle. Selective incorporation of 13C may facilitate the use of 13C-NMR in the study of P450 monooxygenase. Furthermore, selective labeling with 15N or 2H at specific positions within the heme group maybe also be useful in the application of other spectroscopic techniques when applied to P450 enzymes. All of these labeling studies could be accomplished using a recombinant expression system involving a strain of E.coli which cannot produce aminolevulinic acid (ALA), a biosynthetic heme precursor. By synthesizing 2H, 13C or 15N labeled ALA, incorporation of these isotopes into the heme of dehaloperoxidase, a model heme protein, via the biosynthetic pathway of the heme cofactor maybe accomplished. A successfully method was developed to make 2H-ALA in a way that is both economical and time efficient, and the relative ability of this expression system to incorporate 2H into the heme was evaluated, relative to 13C or 15N.

Additional Information

Language: English
Date: 2009
Cytochrome P450 enzymes (P450s), Monooxygenase,
Cytochromes $x Spectroscopic imaging.

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