Serotype-dependent expression patterns of stabilized lipopolysaccharide aggregates in Aggregatibacter actinomycetemcomitans strains.

Microbiol Immunol

Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.

Published: October 2012

Above a critical concentration, amphiphilic lipopolysaccharide (LPS) molecules in an aqueous environment form aggregate structures, probably because of interactions involving hydrophobic bonds. Ionic bonds involving divalent cations stabilize these aggregate structures, making them resistant to breakdown by detergents. The aim of this study was to examine expression patterns of stabilized LPS aggregates in Aggregatibacter actinomycetemcomitans, a microorganism that causes periodontitis. A. actinomycetemcomitans strains of various serotypes and truncated LPS mutants were prepared for this study. Following treatment with a two-phase separation system using the detergent Triton X-114, crude LPS extracts of the study strains were separated into detergent-phase LPS (DP-LPS) and aqueous-phase LPS (AP-LPS). Repeated treatment of the aqueous phase with the two-phase separation system produced only a slight decrease in AP-LPS, suggesting that AP-LPS was resistant to the detergent and thus distinguishable from DP-LPS. The presence of divalent cations increased the yield of AP-LPS. AP-LPS expression patterns were serotype-dependent; serotypes b and f showing early expression, and serotypes a and c late expression. In addition, highly truncated LPS from a waaD (rfaD) mutant were unable to generate AP-LPS, suggesting involvement of the LPS structure in the generation of AP-LPS. The two-phase separation was able to distinguish two types of LPS with different physical states at the supramolecular structure level. Hence, AP-LPS likely represents stabilized LPS aggregates, whereas DP-LPS might be derived from non-stabilized aggregates. Furthermore, time-dependent expression of stabilized LPS aggregates was found to be serotype-dependent in A. actinomycetemcomitans.

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1348-0421.2012.00492.xDOI Listing

Publication Analysis

Top Keywords

expression patterns
12
stabilized lps
12
lps aggregates
12
two-phase separation
12
lps
11
patterns stabilized
8
aggregates aggregatibacter
8
aggregatibacter actinomycetemcomitans
8
actinomycetemcomitans strains
8
aggregate structures
8

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!