Sub-mitochondrial localization of the catalytic subunit of pyruvate dehydrogenase phosphatase.
Using a specific antibody against the PDP catalytic subunit, PDPc, precise localization of this subunit in mitochondria was performed. Sub-fractionation of purified mitochondria by controlled swelling processes led to the isolation of outer membranes, matrix space and inner membrane vesicles which were purified on a sucrose density gradient. In this study, we demonstrated that PDPc was not recovered as a soluble protein in the matrix space but was associated with the inner membrane. Moreover, Triton X-114 phase partitioning performed on inner membranes showed that PDPc behaved both as a hydrophilic and as a hydrophobic protein, thus suggesting two different forms of this enzyme.
Simonot
C
C
Department of Biochemistry, INSERM-CNRS 189, Lyon-Sud Medical School, Oullins, France.
Lerme
F
F
Louisot
P
P
Gateau-Roesch
O
O
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D007425:Intracellular Membranes / Q000201:enzymology; D051379:Mice; D008930:Mitochondria, Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D017830:Octoxynol; D011092:Polyethylene Glycols; D011769:Pyruvate Dehydrogenase (Lipoamide)-Phosphatase / Q000032:analysis*
D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40; D011769:Pyruvate Dehydrogenase (Lipoamide)-Phosphatase