Study of the protein complex, pore diameter, and pore-forming activity of the Borrelia burgdorferi P13 porin
2014 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 289, no 27, 18614-18624 p.Article in journal (Refereed) Published
P13 is one of the major outer membrane proteins of Borrelia burgdorferi. Previous studies described P13 as a porin. In the present study some structure and function aspects of P13 were studied. P13 showed according to lipid bilayer studies a channel-forming activity of 0.6 nanosiemens in 1 M KCl. Single channel and selectivity measurements demonstrated that P13 had no preference for either cations or anions and showed no voltage-gating up to +/-100 mV. Blue native polyacrylamide gel electrophoresis was used to isolate and characterize the P13 protein complex in its native state. The complex had a high molecular mass of about 300 kDa and was only composed of P13 monomers. The channel size was investigated using non-electrolytes revealing an apparent diameter of about 1.4 nm with a 400-Da molecular mass cut-off. Multichannel titrations with different substrates reinforced the idea that P13 forms a general diffusion channel. The identity of P13 within the complex was confirmed by second dimension SDS-PAGE, Western blotting, mass spectrometry, and the use of a p13 deletion mutant strain. The results suggested that P13 is the protein responsible for the 0.6-nanosiemens pore-forming activity in the outer membrane of B. burgdorferi.
Place, publisher, year, edition, pages
American Society for Biochemistry and Molecular Biology, 2014. Vol. 289, no 27, 18614-18624 p.
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
IdentifiersURN: urn:nbn:se:umu:diva-91837DOI: 10.1074/jbc.M113.539528ISI: 000339062900001OAI: oai:DiVA.org:umu-91837DiVA: diva2:741348