Structural and Biochemical Properties of Yarrowia Lipolytica Sterol Carrier Protein-2

PÉREZ DE BERTI, F. J.; FERREYRA, R. G.; BURGARDT, N. I.; CÓRSICO, B.; CEOLÍN, M.R.; ERMÁCORA, M. R.

Montevideo

Congreso; VI International Conference of Biological Physics- ICBP2007, V Southern Cone Biophysics Congress, XXXVI Annual Meeting of the Argentinean Biophysical Society; 2007

International Union of Pure and Applied Physics, International Union for Pure and Applied Biophysics

The sterol carrier protein-2 (SCP-2) is found in genomes from the three super kingdoms of life, and it has been implicated in the transport and metabolism of lipids. We previously have shown that Y. lipolytica sterol carrier protein-2 (YLSCP-2) is a 128‑amino‑acid protein, which is inducible by fatty acids and binds a variety of lipids1. The aim of this work is to study the biochemistry and structure of YLSCP-2. YLSCP-2 purified from Y. lipolytica yeast cells grown on sodium palmitate had 13,944 Da by mass spectrometry, indicating that the induced YLSCP-2 has the initial methionine removed and the following serine N-acetylated. The protein produced by the yeast was impervious to Edman degradation, in accordance with the proposed N-terminal blocking. On the contrary, the recombinant YLSCP-2 expressed in E. coli showed the expected N-terminal processed sequence, and by SEC-FPLC analysis, it behaved as a single specie with a retention time corresponding to a slightly expanded globular protein with the expected size. Crystallization trials with the recombinant protein were carried out and a variety of crystals were obtained. These results allow the structural characterization of the protein and their complexes with atomic resolution.