Chemical characterization of pH-dependent structural epitopes of lipopolysaccharides from Rhizobium leguminosarum biovar phaseoli

Author:

Bhat U R1,Carlson R W1

Affiliation:

1. Complex Carbohydrate Research Center, University of Georgia, Athens 30602.

Abstract

Lipopolysaccharide (LPS) was isolated from free-living Rhizobium leguminosarum bv. phaseoli CE3 cells grown at pH 4.8 (antigenically similar to bacteroid LPS) and compared with that from cells grown at pH 7.2 (free-living bacteria). Composition analysis revealed that pH 7.2 LPS differs from pH 4.8 LPS in that 2,3,4-tri-O-methylfucose is replaced by 2,3-di-O-methylfucose. The amount of 2-O-methylrhamnose is greater in the pH 4.8 LPS than in the pH 7.2 LPS. Analysis of the structural components of LPS (O-chain polysaccharide, core oligosaccharides, and the lipid A) revealed that all the composition differences in the various LPSs occur in the O-chain polysaccharide. These structural variations between pH 4.8 and pH 7.2 LPSs provide a chemical basis for the observed lack of cross-reactivity with pH 4.8 LPS of two monoclonal antibodies, JIM28 and JIM29, raised against free-living bacteria grown at pH 7.2. An LPS preparation isolated from bacteroids contained both 2,3,4-tri-O- and 2,3-di-O-methylfucose residues. This result is consistent with the finding that the two monoclonal antibodies react weakly with bacteroid LPS. It is concluded that methylation changes occur on the LPS O-chain of R. leguminosarum bv. phaseoli when the bacteria are grown at low pH and during nodule development.

Publisher

American Society for Microbiology

Subject

Molecular Biology,Microbiology

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3