权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

The Structure and Biosynthetic Mechanism of the Monomolecular Membrane made of Tetraether Type of Polar Lipids in Methan Menic Bacteria

甲烷细菌四醚型极性脂质单分子膜的结构及生物合成机制

基本信息

批准号：
01560108
负责人：
KOGA Yosuke
金额：
$ 1.34万
依托单位：
University of Occupational and Environmental Health, Japan
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

A pseudomurein-degrading enzyme from Methanobacterium wolfei autolyzate was partially puried to prepare protoplasts of Methanobacterium thermoautotrophicum. An improved assay method of the enzyme using purified cell walls of M. Thermoautotrophicum as a substrate made it possible to determine the enzyme activity quantitatively and to characterize its properties. The optimum pH and temperature were 6.8 - 7.4 and 75 ^ﾟC, respectively. Incubation of this enzyme in the absence of the substrate cell walls at 70 ^ﾟC for 10 min caused loss of half of the activity and heating at 85 ^ﾟC for 10 min inactivated it completely. However, the enzyme activity was recovered more or less by the incubation with the substrate at 62^ﾟC for14 hr even after heat treatment at 100^ﾟC for 30 min. Although the pseudomurein-degrading enzyme was oxygen-sensitive (active only under the anoxic condition), it was also active after storage in the presence of air without reducing agents if it was assayed under the anoxi … More c condition. On the basis of this property the enzyme was able to be purified under normal conditions in the presence of air. Intact cells, protoplasts, and vesicles prepared by passing of a French-pressure cell, of M. Thermoautotrophicum were reacted with trinitrobenzene sulfonic acid and total lipid was extracted. The trinitrophenylated amino lipids and the unreacted lipids were separated by use of thin-layer chromatography and percentage of trinitrophenylation was determined by phosphorus measurement. The vesicles prepared with a French-pressure cell is believed to be inside-out. Archaeitidylethanolamine was almost equally distributed between innerand outer leaflets of the membrane. Approximately 20 % of the amino group of gentiobiosyl caldarchaetidylethanolamine (tetraether type of phosphoglycolipid) oriented to the outside of the membrane. Most (90 %) of the amino groups of archaetidylserine and gentiobisyl caldarchaetidylserine were distributed inner leaflet. This gave another line of evidence for the heptad hypothesis which postulated that tetraether polar lipids were synthesized from diether polar lipids in the membrane without reorientation of those lipids. Less

从沃尔菲甲烷杆菌自溶物中分离纯化了一种假脲醛降解酶，并制备了热自养甲烷杆菌的原生质体。用纯化的M.以热自养菌为底物，可以定量测定酶的活性，并对其性质进行表征。最适pH值为6.8 - 7.4，最适温度为75 ℃。在没有底物细胞壁的情况下，将这种酶在70 ° C下孵育10分钟，会使其失去一半的活性，在85 ° C下加热10分钟会使其完全失活。然而，即使在100 ° C下热处理30分钟后，在62 ° C下与底物孵育14小时，酶活性也或多或少地恢复。尽管假脲醛降解酶是氧敏感的（仅在缺氧条件下有活性），但如果在缺氧条件下测定，则在无还原剂的空气存在下储存后也有活性 ...更多信息 c条件。基于该性质，该酶能够在正常条件下在空气存在下纯化。通过French-pressure细胞，M.热自养菌与三硝基苯磺酸反应，提取总脂。用薄层色谱法分离三硝基苯基化的氨基脂质和未反应的脂质，用磷测定法测定三硝基苯基化的百分率。用法国压力池制备的囊泡被认为是由内而外的。磷脂酰乙醇胺几乎均匀地分布在膜的内外小叶之间。龙胆二糖钙基乙醇胺（四醚型磷酸糖脂）中约20%的氨基位于膜外。古细菌丝氨酸和龙胆草钙细菌丝氨酸的氨基绝大部分（90%）分布在叶片内部.这为七肽假说提供了另一条证据，该假说假设四醚极性脂质是由膜中的二醚极性脂质合成的，而这些脂质没有重新定向。少