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Disintegration of Mg 2+ ‐Induced Hexagonal Assembly of an R‐Form Lipopolysaccharide from Klebsiella pneumoniae by Treatment with CaCl 2
Author(s) -
Ito Hideo,
Naito Setsuko,
Kato Nobuo
Publication year - 2000
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.2000.tb02482.x
Subject(s) - tris , hydroxymethyl , lattice constant , hexagonal crystal system , crystal structure , lipopolysaccharide , klebsiella pneumoniae , crystallography , nuclear chemistry , stereochemistry , chemistry , biology , biochemistry , escherichia coli , physics , diffraction , optics , gene , endocrinology
R‐form lipopolysaccharide (LPS) from Klebsiella pneumoniae strain LEN‐111 (O3—: K1—), which was precipitated by the addition of 2 volumes of ethanol containing 10 m m MgCl 2 for the purification process, ultrastructurally exhibited membrane pieces consisting of an ordered hexagonal lattice structure with a lattice constant of 14 to 15 nm. When the R‐form LPS was suspended in 50 m m tris (hydroxymethyl) aminomethane buffer (at pH 8.5) containing 1 m m or higher concentrations of CaCl 2 and kept at 4 C for 10 hr, the ordered hexagonal lattice structure of the R‐form LPS was disintegrated and changed to an irregular rough, mesh‐like structure. By treatment with CaCl 2 , the content of Mg in the LPS was markedly decreased, and conversely, the content of Ca was increased to a level depending upon the concentration of CaCl 2 . Results indicate that the addition of CaCl 2 to suspensions of the Mg‐bound R‐form LPS result in a tighter binding of Ca 2 to the R‐form LPS and the release of Mg 2 from the R‐form LPS, and as a consequence, destroys the Mg 2+ ‐induced ordered hexagonal lattice structure of the R‐form LPS.