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Crystallization of Lipopolysaccharide from a Salmonella typhimurium Semi‐Rough (SR) Mutant
Author(s) -
Ito Hideo,
Naito Setsuko,
Arakawa Yoshichika,
Sasaki Kyoyu,
Kato Nobuo
Publication year - 1999
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.1348-0421.1999.tb02467.x
Subject(s) - crystallization , lipopolysaccharide , crystallography , salmonella , lipid a , hexagonal crystal system , mutant , polysaccharide , antigen , biology , chemistry , biochemistry , bacteria , organic chemistry , genetics , gene , endocrinology
Salmonella typhimurium SR‐form lipopolysaccharide (LPS), consisting of a single repeating unit of the O‐antigenic polysaccharide, linked to the R‐core consisting of oligosaccharide that is, in turn, linked to lipid A, formed crystals whose shapes were hexagonal plates, discoids, and solid columns when precipitated by the addition of 2 volumes of 95% ethanol containing 375 mM MgCl 2 and kept in 70% ethanol containing 250 mM MgCl 2 at 4 C for 10 days. Among these crystals, the basic form is considered to be the hexagonal plates. Analyses of hexagonal plate crystals showed that they consist of hexagonal lattices with a lattice constant ( a axis) of 4.62 Å and longitudinal axis ( c axis) of approximately 100 Å. In X‐ray diffraction patterns in the low‐angle region, crystals of S. typhimurium SR‐form LPS exhibited much less distinct reflections when compared with crystals of synthetic Escherichia coli ‐type lipid A. In contrast to the previous finding that S. minnesota S‐form LPS possessing the O‐antigenic polysaccharide does not crystallize under the same experimental conditions as used in the present study, the presence of a single repeating unit of the O‐antigenic polysaccharide does not inhibit crystallization.