Structural properties of caleosin: A MS and CD study

Zita Purkrtova (1, 2) , Sabine D’andrea (1) , Pascale Jolivet (3) , Petra Lipovova (4) , Blanka Kralova (2) , Milan Kodicek (2) , Thierry Chardot (3)

1 UCB - Chimie Biologique
2 Department of Biochemistry and Microbiology
3 UCB - Chimie Biologique
4 UCT Prague - University of Chemistry and Technology Prague

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.

Keywords: arabidopsis thaliana; seeds; oil bodies; caleosin; circular dichroism

Domains: Life Sciences [q-bio]

Zita Purkrtova, Sabine D’andrea, Pascale Jolivet, Petra Lipovova, Blanka Kralova, et al.. Structural properties of caleosin: A MS and CD study. Archives of Biochemistry and Biophysics, 2007, 464 (2), pp.335-343. ⟨10.1016/j.abb.2007.04.041⟩. ⟨hal-03659064⟩