New insights into the composition, molecular mass and stoichiometry of the protein complexes of plant mitochondria

• Published in: The Plant journal : for cell and molecular biology 1996-03, Vol.9 (3), p.357-368
• Main Authors: Jänsch, Lothar, Kruft, Volker, Schmitz, Udo K., Braun, Hans‐Peter
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Arabidopsis - chemistry; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis thaliana; Biological and medical sciences; Cell biochemistry; Cell physiology; Cell structures and functions; Electrophoresis, Polyacrylamide Gel - methods; Fundamental and applied biological sciences. Psychology; Mitochondria - chemistry; Mitochondria and cell respiration; Molecular and cellular biology; Molecular Sequence Data; Molecular Weight; Plant physiology and development; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - isolation & purification; Protein Conformation; Protein Denaturation; Proton-Translocating ATPases - chemistry; Proton-Translocating ATPases - genetics; Proton-Translocating ATPases - isolation & purification; Solanum tuberosum - chemistry; Solanum tuberosum - genetics; Solubility
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313X.1996.09030357.x

Recently a powerful electrophoresis method for the native preparation and characterization of the respiratory protein complexes of mitochondria from fungi and mammals has been developed, which employs Coomassie dyes to introduce charge shifts on proteins (Schägger and von Jagow (1991) Anal. Biochem. 199, 223–231). The procedure, which is called ‘blue native‐polyacrylamide gel electrophoresis’ (BN‐PAGE), was modified and introduced for the analysis of mitochondria from higher plants. BN‐PAGE of mitochondrial protein from potato allows the separation of nine distinct protein complexes between 100 and 1000 kDa and reveals novel results for their composition, molecular mass and stoichiometry. For the first time soluble mitochondrial protein complexes, like the HSP60 complex (750 kDa) and a complex of 200 kDa, which includes a formate dehydrogenase, are analysed by BN‐PAGE. Complex I from potato (1000 kDa) is about 100 kDa larger than the corresponding enzyme from beef and can be resolved into more than 30 different subunits on a second gel dimension. The F1F0 ATP synthase (580 kDa) and the cytochrome c oxidase (160 kDa) from potato seem to contain more subunits than hitherto reported. Direct sequencing of subunits revealed that the F1 part of the F1F0 ATP synthase lacks the oligomycin sensitivity conferring protein (OSCP), which was reported to be present in F1 parts of dicotyledonous plants, but contains the ATPase inhibitory protein. N‐terminal sequences of 16 mitochondrial proteins were obtained, several of which are presented for the first time from a plant source. BN‐PAGE allows the preparation of mitochondrial protein complexes from gram amounts of plant tissue, as the procedure only requires milligram amounts of organelles. This potential of BN‐PAGE is demonstrated by the separation and characterization of the mitochondrial enzyme complexes from Arabidopsis thaliana. Further analysis of organellar protein complexes by BN‐PAGE will allow the generation of ‘protein maps’ from different tissues and developmental stages or from mutant plants.