De March Matteo, Brancatelli Giovanna, Demitri Nicola, De Zorzi Rita, Hickey Neal, Geremia Silvano
Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Trieste, Italy.
IUBMB Life. 2015 Sep;67(9):694-700. doi: 10.1002/iub.1410. Epub 2015 Aug 26.
Using our previously reported maps of the electrostatic surface of horse heart ferri- and ferro-cyt c, comparisons were made between the complementary electrostatic surfaces of three cyt c peroxidase-cyt c complexes and the photosynthetic reaction center-cyt c complex, considering both iron oxidation states. The results obtained were consistent with a sliding mechanism for the electron shuttle on the surface of the protein complexes, promoted by the change in iron oxidation state. This mechanism was found to be in agreement with theoretical and NMR studies reported in the literature. Importantly, the analysis also provided a rationale for recognition of nonproductive associations. As we have previously reported the same conclusion on examination of redox partners of cyt c in the mitochondrial respiratory pathway, our hypothesis is that the proposed mechanism could represent a general exit strategy of monoheme cyts c and c2 in electron transfer complexes.
利用我们之前报道的马心铁细胞色素c和亚铁细胞色素c的静电表面图谱，考虑到两种铁氧化态，对三种细胞色素c过氧化物酶-细胞色素c复合物以及光合反应中心-细胞色素c复合物的互补静电表面进行了比较。所得结果与蛋白质复合物表面电子穿梭的滑动机制一致，该机制由铁氧化态的变化所推动。发现该机制与文献中报道的理论和核磁共振研究结果相符。重要的是，该分析还为识别非生产性结合提供了理论依据。由于我们之前在检查线粒体呼吸途径中细胞色素c的氧化还原伙伴时也得出了相同的结论，我们的假设是，所提出的机制可能代表了单血红素细胞色素c和c2在电子传递复合物中的一种通用退出策略。
