title: Brassica napus plastid and mitochondrial chaperonin-60 proteins contain multiple distinct polypeptides.
abstract: Plastid chaperonin-60 protein was purified to apparent homogeneity from Brassica napus using a novel protocol. The purified protein, which migrated as a single species by nondenaturing polyacrylamide gel electrophoresis, contained four polypeptides: three variants of p60cpn60 alpha and p60cpn60 beta. Partial amino acid sequence determination demonstrated that each variant of p60cpn60 alpha is a distinct translation product. During this study, additional chaperonin-60 proteins were purified. These proteins, which were free from contaminating plastid chaperonin-60, were separated into at least two high molecular weight species that were resolved only by nondenaturing polyacrylamide gel electrophoresis. These proteins contained three 60-kD polypeptides. Two of these polypeptides were recognized by existing antisera, whereas the third was not. Partial amino acid sequence data revealed that each of these, including the immunologically distinct polypeptide, is a chaperonin-60 subunit of putative mitochondrial origin. The behavior of chaperonin-60 proteins during blue A Dyematrex chromatography suggests that this matrix may be generally useful for the identification of chaperonin-60 proteins.
authors.affiliation: Plant Biotechnology Institute, National Research Council, Saskatoon, Saskatchewan, Canada.
authors.forename: L P
authors.initials: LP
authors.lastname: Cloney
authors.forename: D R
authors.initials: DR
authors.lastname: Bekkaoui
authors.forename: G L
authors.initials: GL
authors.lastname: Feist
authors.forename: W S
authors.initials: WS
authors.lastname: Lane
authors.forename: S M
authors.initials: SM
authors.lastname: Hemmingsen
mesh_terms: D000595:Amino Acid Sequence; D001937:Brassica / Q000378:metabolism*; D018833:Chaperonins; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D018087:Plastids / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid
chemical_list: D010940:Plant Proteins; D011506:Proteins; D018833:Chaperonins