BARLEY LIPID TRANSFER PROTEIN 1 WITH A COVALENTLY ATTACHED LIPID-LIKE MOLECULE

Jitka Žídková¹, Jozef Hritz², Michaela Matejková³, Lukáš Žídek³, Vladimír Sklenář³, Janette Bobáľová¹

¹Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, v.v.i., Veveří 97, 60200 Brno, Czech Republic

²Department of Pharmacochemistry, Vrije Universiteit, De Boelelaan 1083, NL-1081 HV Amsterdam, The Netherlands

³National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 61137 Brno, Czech Republic

zidkova@iach.cz

Lipid transfer protein 1 (LTP1) from barley is a small protein able to transfer lipids across a membrane in vitro. Its physiological role is not clear, it has been proposed to be involved in cutin synthesis and plant defense mechanism. LTP1 is also important commercially, as it has an effect on beer foam formation. Interestingly, LTP1 isolated from barley flour is almost completely covalently modified with 9-hydroxy-10-oxo-12-Z-octadecenoic acid, bound to Asp 7 via an ester bond. The lipid modification alters physico-chemical properties of the protein and contributes to its unusual heat stability. An X-ray structure of the lipid-modified protein (LTP1b) has been published recently (3GSH.PDB). In our study, we clarify some ambiguities related to the resolution of the bound lipid in the X-ray structure and present complementary NMR data illustrating dynamic behavior of the protein. In addition, we describe a computational protocol used to predict the 3D structure of LTP1b without a knowledge of the X-ray structure, based on a docking approach.

Acknowledgments

This work was supported by the Grants 1M0570, MSM0021622413, and LC06030 of the Ministry of Education, Youth, and Physical Culture of the Czech Republic, and by Grant AV0Z40310501 of the Academy of Sciences of the Czech Republic.