Isolation and characterization of OmpF-like porin from Yersinia ruckeri

• Published in: Biochemistry (Moscow). Supplement series A, Membrane and cell biology Vol. 6; no. 3; pp. 235 - 242
• Main Authors: Chistyulin, D. K., Novikova, O. D., Portnyagina, O. Yu, Khomenko, V. A., Vakorina, T. I., Kim, N. Yu, Isaeva, M. P., Likhatskaya, G. N., Solov’eva, T. F.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01.07.2012; Springer Nature B.V
• Subjects: Amino acid sequence; Biochemistry; Biomedical and Life Sciences; C.D; Cell Biology; Cellular biology; Channel pores; Fluorescence; Gram-negative bacteria; Life Sciences; Lipid membranes; Membranes; Microorganisms; Molecular weight; Outer membranes; Polypeptides; Porins; Protein structure; Proteins; Spectroscopy; Temperature effects; Thermal stability; Yersinia; Yersinia ruckeri; Yersiniosis; outer membrane; Gram-negative bacteria; pore-forming proteins
• ISSN: 1990-7478; 1990-7494
• DOI: 10.1134/S1990747812030038

The polypeptide profile of the porin protein fraction of Yersinia ruckeri , a Gram-negative bacterium causing yersiniosis in fish, has been shown to depend on cultivation temperature. OmpF-like porins are expressed mainly in the outer membrane (OM) of the “cold” variant (4°C) of the microorganism and OmpC-like proteins are expressed in the OM of the “warm” variant (37°C). Both types of porins are present in the OM of Y. ruckeri at room temperature. The OmpF-like porin of the “cold” variant was isolated and characterized. The molecular weight and primary structure of the protein were determined. The methods of optical spectroscopy (circular dichroism and intrinsic protein fluorescence) have shown that the protein has a spatial structure typical of β-structured porins from the OM of Gram-negative bacteria. The functional activity of isolated protein was characterized by the bilayer lipid membrane (BLM) technique. The most probable level of channel conductivity was 320 ± 60 pS, corresponding to the channel conductivity of OmpF porins of the genus Yersinia. The distinctive feature of OmpF porin from Y. ruckeri is high thermostability of its functionally active conformation: the protein forms stable pores in the BLM even after heating to 85°C.