Acyl chain composition determines cardiolipin clustering induced by mitochondrial creatine kinase binding to monolayers.
It has been recently shown that mitochondrial creatine kinase (mtCK) organizes mitochondrial model membrane by modulating the state and fluidity of lipids and by promoting the formation of protein-cardiolipin clusters. This report shows, using Brewster angle microscopy, that such clustering is largely dependent on the acyl chain composition of phospholipids. Indeed, mtCK-cardiolipin domains were observed not only with unsaturated cardiolipins, but also with the cardiolipin precursor phosphatidylglycerol. On the other hand, in the case of saturated dimyristoylphosphatidylglycerol and tetramyristoylcardiolipin, mtCK was homogeneously distributed underneath the monolayer. However, an overall decrease in membrane fluidity was indicated by infrared spectroscopy as well as by extrinsic fluorescence spectroscopy using Laurdan as a fluorescent probe, both for tetramyristoylcardiolipin and bovine heart cardiolipin containing liposomes. The binding mechanism implicated the insertion of protein segments into monolayers, as evidenced from alternative current polarography, regardless of the chain unsaturation for the phosphatidylglycerols and cardiolipins tested.
Université de Lyon, Université Lyon 1, F-69622 Villeurbanne, France.
Ofelia
O
Maniti
Mouhedine
M
Cheniour
Marie-France
MF
Lecompte
Olivier
O
Marcillat
René
R
Buchet
Christian
C
Vial
Thierry
T
Granjon
D000818:Animals; D001665:Binding Sites; D002308:Cardiolipins / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D052281:Creatine Kinase, Mitochondrial Form / Q000378:metabolism*; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism*; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism; D008853:Microscopy / Q000379:methods; D024101:Mitochondrial Proteins / Q000378:metabolism*; D010715:Phosphatidylglycerols / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared
D002308:Cardiolipins; D008051:Lipid Bilayers; D008563:Membrane Lipids; D024101:Mitochondrial Proteins; D010715:Phosphatidylglycerols; C002773:dimyristoylphosphatidylglycerol; D052281:Creatine Kinase, Mitochondrial Form