Observation of heme transfer from cytochrome b5 to DNA aptamer.

Ying-Wu Lin, Mei-Hui Sun, Dun Wan, Li-Fu Liao

Index: Spectrochim. Acta. A. Mol. Biomol. Spectrosc. 96 , 365-9, (2012)

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Abstract

Heme transfer is commonly observed from one heme protein to the other such as from cytochrome b(5) (cyt b(5)) to apo-myoglobin. In this study, instead of to another heme protein, we observed the heme transfer from wild-type (WT) cyt b(5), H39C cyt b(5) with heme axial ligand His39 mutated to Cys39, and DME cyt b(5) with heme replaced by protoporphyrin IX dimethyl ester, to a heme DNA aptamer, PS2.M, respectively, with a different rate constant. The heme transfer was further confirmed by the enhancement of peroxidase activity of the cyt b(5)s-PS2.M system due to the formation of catalytic PS2.M-heme complex. This study provides valuable insights into both cyt b(5)-heme and PS2.M-heme interactions and shows that heme transfer from heme protein to heme-aptamer can be used to evaluate the relative stability of heme proteins. In addition, this study sheds light on the maturation of heme proteins in vivo by interacting with DNA/RNA enzymes.Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.