title: Analyzing Structural Properties of Heterogeneous Cardiolipin-Bound Cytochrome C and Their Regulation by Surface-Enhanced Infrared Absorption Spectroscopy.
abstract: Apoptotic mechanisms are not fully understood due to limitations in present analytical methods. Such understanding may be advanced by unravelling the structural properties of heterogeneous cardiolipin (CL)-bound cytochrome c (cyt c) and the factors or events that regulate them. In this study, surface-enhanced infrared absorption spectroscopy (SEIRAS) was employed to probe the adsorption of cyt c on CL membranes in biomimetic conditions. The results clearly show that pure electrostatic interactions result in the unfolding of partial α-helices, while the synergy between hydrogen bonding and electrostatic interactions governs orientation homogeneity of adsorbed protein, and conformational transition between α-helices and β-sheet. Hydrogen bonding plays a dual role; along with hydrophobic interactions, it may disturb the microenvironment of some secondary structures such as the β-turn type III, while it also triggers structural changes in lipid molecules likely resulting from the extension of CL acyl chains to the hydrophobic channels of cyt c. These findings provide the details of protein transitions in early apoptosis at the molecular level.
authors: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, Jilin 130022, China.|University of Chinese Academy of Sciences , Beijing 100049, China.
authors: Li
authors: L
authors: Zeng
authors: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, Jilin 130022, China.
authors: Lie
authors: L
authors: Wu
authors: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, Jilin 130022, China.
authors: Li
authors: L
authors: Liu
authors: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, Jilin 130022, China.
authors: Xiue
authors: X
authors: Jiang
mesh_terms: D000327:Adsorption; D002308:Cardiolipins / Q000737:chemistry* / Q000378:metabolism; D045304:Cytochromes c / Q000737:chemistry* / Q000378:metabolism; D055664:Electrochemical Techniques; D006860:Hydrogen Bonding; D007700:Kinetics; D013055:Spectrophotometry, Infrared; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D002308:Cardiolipins; D045304:Cytochromes c