| Regional Biophysics Meeting 2005, March 16-20, Zreče, Slovenia | [ProtBiophys] |
ESR STUDY OF SPIN LABELLED OVALBUMIN Marija Brgles1, Krunoslav Mirosavljević2, Ruža Frkanec1, Vesna Noethig Laslo2, and Jelka Tomašić1 1Institute of Immunology, Inc., Rockefellerova 10, 10 000 Zagreb, Croatia 2Rudjer Bošković Institute, Bijenička 54, 10 000 Zagreb, Croatia Method for the spin labelling of ovalbumin was developed. Interactions of spin labelled ovalbumin (SL-OVA) with multilayer liposomes and immunostimulating peptidoglycan monomer were investigated by Electron Spin Resonance (ESR) spectroscopy. Ovalbumin (OVA) is the major protein in avian egg-white. It belongs to the serpin (serine protease inhibitors) family but it lacks any protease inhibitory activity. Among the others OVA has been used as a model protein antigen in our investigations of adjuvant effects of immunostimulating peptides [1]. Spin labelling was succesfully applied in the study of interactions of peptidoglycan monomer and structurally related adamantyltripeptides with lipid bilayers in liposomes [2]. The aim of the present study has been to investigate the possible interactions of OVA with immunostimulating peptides and with liposomal bilayers by (ESR). Ovalbumin was spin labelled with 4-maleimido-2,2,6,6,-tetrametylpiperidine-1-oxsil (TEMPO-maleimide) that binds covalently to -SH groups of cisteins and terminal amino groups of lysines. Presence of two motionally different populations of the spin labels were determined from the ESR spectra of the spin labelled ovalbumin: with a highly restricted motion relative to the protein, located far from the protein surface, and with free motion located at the protein surface. [1] J. Tomašić, I. Hanzl-Dujmović, B. Špoljar, B. Vranešić, M. Šantak, A. Jovičić, Vaccine 18 (2000) 1236-1243. [2] R. Frkanec, V. Noethig Laslo, B. Vranešić, K. Mirosavljević and J. Tomašić, Biochim. Biophys. Acta, 1611 (2003) 187-195.
Email: mbrgles@imz.hr
Address: Institute of Immunology Inc., P.O.Box 266, Rockefellerova 10, 10 000 Zagreb, Croatia