Reference: Hielscher R, et al. (2009) Monitoring the redox and protonation dependent contributions of cardiolipin in electrochemically induced FTIR difference spectra of the cytochrome bc(1) complex from yeast. Biochim Biophys Acta 1787(6):617-25

Reference Help

Abstract


Biochemical studies have shown that cardiolipin is essential for the integrity and activity of the cytochrome bc(1) complex and many other membrane proteins. Recently the direct involvement of a bound cardiolipin molecule (CL) for proton uptake at center N, the site of quinone reduction, was suggested on the basis of a crystallographic study. In the study presented here, we probe the low frequency infrared spectroscopy region as a technique suitable to detect the involvement of the lipids in redox induced reactions of the protein. First the individual infrared spectroscopic features of lipids, typically present in the yeast membrane, have been monitored for different pH values in micelles and vesicles. The pK(a) values for cardiolipin molecule have been observed at 4.7+/-0.3 and 7.9+/-1.3, respectively. Lipid contributions in the electrochemically induced FTIR spectra of the bc(1) complex from yeast have been identified by comparing the spectra of the as isolated form, with samples where the lipids were digested by lipase-A(2). Overall, a noteworthy perturbation in the spectral region typical for the protein backbone can be reported. Interestingly, signals at 1159, 1113, 1039 and 980 cm(-1) have shifted, indicating the perturbation of the protonation state of cardiolipin coupled to the reduction of the hemes. Additional shifts are found and are proposed to reflect lipids reorganizing due to a change in their direct environment upon the redox reaction of the hemes. In addition a small shift in the alpha band from 559 to 556 nm can be seen after lipid depletion, reflecting the interaction with heme b(H) and heme c. Thus, our work highlights the role of lipids in enzyme reactivity and structure.

Reference Type
Journal Article | Research Support, Non-U.S. Gov't
Authors
Hielscher R, Wenz T, Hunte C, Hellwig P
Primary Lit For
Additional Lit For
Review For

Gene Ontology Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene/Complex Qualifier Gene Ontology Term Aspect Annotation Extension Evidence Method Source Assigned On Reference

Phenotype Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details.

Gene Phenotype Experiment Type Mutant Information Strain Background Chemical Details Reference

Disease Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene Disease Ontology Term Qualifier Evidence Method Source Assigned On Reference

Regulation Annotations


Increase the total number of rows displayed on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; to filter the table by a specific experiment type, type a keyword into the Filter box (for example, “microarray”); download this table as a .txt file using the Download button or click Analyze to further view and analyze the list of target genes using GO Term Finder, GO Slim Mapper, SPELL, or YeastMine.

Regulator Target Direction Regulation Of Happens During Method Evidence

Post-translational Modifications


Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through its pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Site Modification Modifier Reference

Interaction Annotations


Genetic Interactions

Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.

Interactor Interactor Allele Assay Annotation Action Phenotype SGA score P-value Source Reference

Physical Interactions

Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.

Interactor Interactor Assay Annotation Action Modification Source Reference

Functional Complementation Annotations


Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through its pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene Species Gene ID Strain background Direction Details Source Reference