The function of teichoic acids in cation control in bacterial membranes

Author:

Hughes A. H.1,Hancock I. C.1,Baddiley J.1

Affiliation:

1. Microbiological Chemistry Research Laboratory, School of Chemistry, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, U.K.

Abstract

1. The effects of teichoic acids on the Mg2+-requirement of some membrane-bound enzymes in cell preparations from Bacillus licheniformis A.T.C.C. 9945 were examined. 2. The biosynthesis of the wall polymers poly(glycerol phosphate glucose) and poly(glycerol phosphate) by membrane-bound enzymes is strongly dependent on Mg2+, showing maximum activity at 10–15mm-Mg2+. 3. When the membrane is in close contact with the cell wall and membrane teichoic acid, the enzyme systems are insensitive to added Mg2+. The membrane appears to interact preferentially with the constant concentration of Mg2+ that is bound to the phosphate groups of teichoic acid in the wall and on the membrane. When the wall is removed by the action of lysozyme the enzymes again become dependent on an external supply of Mg2+. 4. A membrane preparation that retained its membrane teichoic acid was still dependent on Mg2+ in solution, but the dependence was damped so that the enzymes exhibited near-maximal activity over a much greater range of concentrations of added Mg2+; this preparation contained Mg2+ bound to the membrane teichoic acid. The behaviour of this preparation could be reproduced by binding membrane teichoic acid to membranes in the presence of Mg2+. Addition of membrane teichoic acid to reaction mixtures also had a damping effect on the Mg2+ requirement of the enzymes, since the added polymer interacted rapidly with the membrane. 5. Other phosphate polymers behaved in a qualitatively similar way to membrane teichoic acid on addition to reaction mixtures. 6. It is concluded that in whole cells the ordered array of anionic wall and membrane teichoic acids provides a constant reservoir of bound bivalent cations with which the membrane preferentially interacts. The membrane teichoic acid is the component of the system which mediates the interaction of bound cations with the membrane. The anionic polymers in the wall scavenge cations from the medium and maintain a constant environment for the membrane teichoic acid. Thus a function of wall and membrane teichoic acids is to maintain the correct ionic environment for cation-dependent membrane systems.

Publisher

Portland Press Ltd.

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