title: [Effect of a lipopolysaccharide on the conformational state and functional activity of a Yersinia pseudotuberculosis porin].
abstract: Changes in the structure and functional activity of porin, a protein from Yersinia pseudotuberculosis, resulting from the removal of lipopolysaccharide (LPS) normally bound with the protein were studied. The treatment of LPS-containing porin with a 30% SDS solution led to an LPS-free protein that, according to the SDS-PAGE, remained to be a trimer. It was shown by CD and UV spectroscopies and intrinsic protein fluorescence that the removal of LPS caused only conformational changes in the porin secondary and tertiary structures. The LPS-free porin folded into a completely beta-structured protein aggregate. The bilayer lipid membrane technique showed that the pore-forming activity of the LPS-free porin decreased, and its concentration should be increased by two orders of magnitude to achieve the same effect. Incubation of the LPS-free porin with LPS led to a porin-LPS complex and affected the character of the protein functional activity. The treatment of the LPS-free porin by octyl glucoside, a nonionic detergent, resulted in the restoration of the protein pore-forming activity. It was suggested that the LPS and detergent provide a definite protein conformation necessary for its functioning.
authors.affiliation: Pacific Institute of Bioorganic Chemistry, Far East Division, Russian Academy of Sciences, Vladivostok, Russia. novikova@piboc.marine.su
authors.forename: O D
authors.initials: OD
authors.lastname: Novikova
authors.forename: N Iu
authors.initials: NIu
authors.lastname: Kim
authors.forename: V P
authors.initials: VP
authors.lastname: Glazunov
authors.forename: T I
authors.initials: TI
authors.lastname: Vakorina
authors.forename: G A
authors.initials: GA
authors.lastname: Naberezhnykh
authors.forename: G N
authors.initials: GN
authors.lastname: Likhatskaia
authors.forename: V A
authors.initials: VA
authors.lastname: Khomenko
authors.forename: T F
authors.initials: TF
authors.lastname: Solov'eva
mesh_terms: D002850:Chromatography, Gel; D002942:Circular Dichroism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D018272:Porins / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D015011:Yersinia pseudotuberculosis / Q000737:chemistry*
chemical_list: D008070:Lipopolysaccharides; D018272:Porins