Cardiolipin Activates Cytochrome c Peroxidase Activity Since It Facilitates H₂O₂ Access to Heme

---

Yu. A. Vladimirov^1*, E. V. Proskurnina¹, D. Yu. Izmailov¹, A. A. Novikov², A. V. Brusnichkin³, A. N. Osipov², and V. E. Kagan⁴

¹Faculty of Basic Medicine, Lomonosov Moscow State University, Lomonosovsky pr. 31/5, 117192 Moscow, Russia; fax: (495) 932-8814; E-mail: yuvlad@mail.ru

²Russian State Medical University, ul. Ostrovityanova 1, 117997 Moscow, Russia; E-mail: anosipov@yahoo.com

³Chemical Faculty, Lomonosov Moscow State University, Vorob'evy Hills 1/3, 119992 Moscow, Russia; E-mail: x6f.rebel@rambler.ru

⁴University of Pittsburgh, 100 Technology Dr., Suite 333, 15260 Pittsburgh, PA, USA; E-mail: vkagan@ceoh.pitt.edu

^* To whom correspondence should be addressed.

Received January 11, 2006; Revision received June 2, 2006

---

In this work, the effect of liposomes consisting of tetraoleyl cardiolipin and dioleyl phosphatidylcholine (1 : 1, mol/mol) on the rate of three more reactions of Cyt c heme with H₂O₂ was studied: (i) Cyt c (Fe²⁺) oxidation to Cyt c (Fe³⁺), (ii) Fe···S(Met80) bond breaking, and (iii) heme porphyrin ring decomposition. It was revealed that the rates of all those reactions increased greatly in the presence of liposomes containing cardiolipin and not of those consisting of only phosphatidylcholine, and approximately to the same extent as peroxidase activity. These data suggest that cardiolipin activates specifically Cyt c peroxidase activity not only because it promotes Fe···S(Met80) bond breaking but also facilitates H₂O₂ penetration to the reaction center.

---

KEY WORDS: cytochrome c, cardiolipin, peroxidase activity, apoptosis, hydrogen peroxide, chemiluminescence, heme, A₆₉₅

DOI: 10.1134/S0006297906090082

---