Isolation and Characterization of the Immunoglobulin-Binding Protein from Yersinia pseudotuberculosis

G. A. Naberezhnykh^*, E. V. Sidorin, P. S. Dmitrenok, N. Yu. Kim, and T. F. Solov'eva

Pacific Institute of Bioorganic Chemistry, Far East Division of the Russian Academy of Sciences, pr. 100-letiya Vladivostoka 159, Vladivostok, 690022 Russia; fax: (4232) 314-050; E-mail: naber@piboc.dvo.ru

^* To whom correspondence should be addressed.

Received August 15, 2001; Revision received October 17, 2001

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A high molecular weight immunoglobulin-binding protein localized on the surface of bacterial cells has been isolated from the protein fraction of the outer membrane of Yersinia pseudotuberculosis, and its properties are described. The immunoglobulin-binding protein is a trypsin-resistant and temperature-sensitive beta-structured protein. As shown by MALDI-TOF mass spectrometry, after heating at 100°C the molecular weight of the protein constituted 37.5 kD. The native protein is capable of interacting with human and rabbit IgG but looses the ability to bind the immunoglobulins after the temperature denaturation. The immunoglobulin-binding protein binds to the Fc-fragments of the immunoglobulins and binding depends on the presence of calcium ions.

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KEY WORDS: immunoglobulins, membrane proteins, immunoglobulin-binding proteins

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