Structural properties of caleosin: a MS and CD study.
We have investigated the covalent and secondary solution structure of caleosin, a 27-kDa protein also called ATS1 or AtClo1 (At4g26740) found within Arabidopsis thaliana seed lipid bodies. The native protein was partly phosphorylated at S225. Purified bacterially expressed caleosin (recClo) was not phosphorylated; cysteine residues C221 and C230 were connected by a disulfide bridge. In solution it exists as a mixture of predominant monomers and covalent dimers. We have used recClo as a model for the study of AtClo1 secondary structure. recClo is folded in aqueous solution (16% alpha-helix, 29% beta-sheet), its secondary structure being dramatically influenced by the polarity of media, as deduced from CD spectra measured in the presence of increasing concentrations of various aliphatic alcohols.
Purkrtova
Zita
Z
UMR 206 Chimie Biologique, Agro Paris Tech, INRA, BP1, F-78850 Thiverval Grignon, France.
d'Andrea
Sabine
S
Jolivet
Pascale
P
Lipovova
Petra
P
Kralova
Blanka
B
Kodicek
Milan
M
Chardot
Thierry
T
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000737:chemistry*; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D002942:Circular Dichroism; D013058:Mass Spectrometry; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D012639:Seeds / Q000737:chemistry*
D002135:Calcium-Binding Proteins; D010940:Plant Proteins; C402836:caleosin protein, Sesamum indicum