Acyl chain composition determines cardiolipin clustering induced by mitochondrial creatine kinase binding to monolayers

►Formation of mtCK-cardiolipin clusters depends on CL acyl chain composition. ►mtCK induces clustering of unsaturated egg yolk PG, but not of saturated DMPG. ►mtCK reduces membrane fluidity both for TMCL and bovine heart CL-containing liposomes. ►Protein segments penetrate both saturated TMCL and DMPG and unsaturated bovine heart CL and PG monolayers. ►Protein domain movements occur after binding to saturated and unsaturated cardiolipins or phosphatidylglycerols, with the highest amplitude observed for bovine heart CL.