Teichoic acids membrane

Klosinski, P., Penczek, S. Teichoic Acids and Their Models Membrane Biopolymers withPolphosphate Backbones. Synthesis, Structure and Properties. Vol. 79, pp. 139—157. 

Baddiley, J. (1989). Bacterial cell walls and membranes. Discovery of the teichoic acids, Bioessays, 10, 207-210. 

Teichoic acids are often covalently attached to glycolipids which are part of the plasma membrane. For example, the glycerolteichoic acid of Streptococcus faecium contains about 28 monomer units of glycerol phosphate, approximately 60% of which carry residues of kojibiose (Glual —> 2Glu) as a phosphatidylkojibiosyl diacylglycerol membrane anchor.600 Teichuronic acids contain uronic acids ... 

Although it would be out of place to give here an extensive account of the surface anatomy of bacteria, current interest in the exact location of compounds in the anatomical components of cells, for example, in membranes, granules, mitochondria, and ribosomes, requires a reasonably precise description of the location of teichoic acids. In its turn, this requires an understanding of the main features of the outer regions of bacteria. Gram-positive bacteria possess a rigid cell-wall which is responsible for... 

Membrane teichoic acids have now been detected in a large number of bacteria, including almost all of the Gram-positive organisms examined. Nevertheless, the proportion present is sometimes small, and separation of the acids from other macromolecular cell-components, such as nucleic acids, peptides, and polysaccharides, is difficult. Consequently, few have been obtained in an amount and of a purity adequate for detailed chemical study. Even from the limited studies so far made, it is clear that structural details differ considerably from case to case, and it is convenient to classify these teichoic acids according to the organisms from which they have been isolated. 

This was the first membrane teichoic acid to be studied and, although the walls of this organism do not contain a teichoic acid, difficulties were experienced in the purification of the material isolated from extracts of... 

The walls of Gram-positive bacteria, unlike the membranes, sometimes do not contain teichoic acids. However, there are numerous examples of walls which do contain these compounds in substantial proportions, although in relatively few cases has detailed structural work been carried out. The purification of wall teichoic acids is often much more readily achieved than for the membrane polymers. Addition of ethanol to trichloroacetic acid extracts of walls gives a precipitate which is usually pure teichoic acid. Extraction is effected at low temperatures, and for a reasonably short time, in order to avoid extensive degradation of the polymers under the acidic conditions. Consequently, although walls may contain 20-50% by weight of teichoic acid, practiced yields are generally rather low. 

The nature of the association between membrane and teichoic acid is unknown, and it is possible that these teichoic acids are chemically attached to other components of the cell. Samples obtained by extraction with phenol appear to have appreciably higher molecular weight than has the purified teichoic acid obtained by extraction with trichloroacetic acid, and it is likely that the prolonged, acid treatment used in earlier work may have caused hydrolysis of some of the phosphodiester linkages. It is noteworthy that this comment on earlier studies does not apply to ribitol teichoic acids. Detailed examination of preparations of membrane teichoic acid obtained by less drastic conditions is highly desirable, in order to confirm the supposed size of the naturally occurring polymers, as well as... 

Poly(ribitol phosphate) synthetase has been found in particulate fractions from Staphylococcus aureus H, and Lactobacillus plantatrum.lt ll-m The bulk of the activity in Lactobacillus plantarum was in crude, cell-wall preparations, and the enzyme is apparently located in the membrane, although intimate association with the wall itself has been suggested. Unlike the natural teichoic acid, the enzymically synthesized ribitol phosphate polymer was readily extracted with phenol hydrolysis by acid and by alkali gave the expected products, and oxidation with periodate indicated a chain length of 5-9 units, a value which compares well with that of 8 units for the natural polymer in the walls of this organism. 

Synthetic ribitol phosphate polymer, unlike teichoic acid in a wall, is readily extracted from the particulate enzyme or membrane preparation by treatment with phenol.18 Similarly, teichoic acid synthesized by intact cells in the presence of penicillin is only loosely attached to the wall,111 and it may be significant that, in each case, synthesis of teichoic acid has occurred without the simultaneous synthesis of glycosaminopeptide. It is now known that, in the normal wall, teichoic acid and glycosaminopeptide are attached to each other, and it has been suggested that the low activity of cell-free synthetase is due to the absence of suitable acceptor molecules of glycosaminopeptide. This possibility could account for the ease of removal of teichoic acid formed when simultaneous synthesis of glycosaminopeptide was not possible. 

Teichoic acids (TAs), naturally occurring polyphosphates of substituted glycerol (7) or ribitol (2) in the simpler cases, are biopolymers isolated from the cell walls (wall TAs) or membranes [membrane TAs or lipoteichoic acids (LTAs)] of various Grampositive bacteria ... 

The teichoic acids of the wall and membrane act as a buffer system maintaining a concentration of Mg2 in the range of 10-15 mM, which is the optimum value for the activity of enzymes associated with membranes 31). Changes of the Mg2 + concentration in the medium have no effect on the activity of membrane-bound enzymes if the system keeps both the membrane and the cell wall closely in contact. Preparations devoid of cell walls (lysozyme digestion) exhibit a dependence of enzyme activity on the Mg2 + concentration. The membrane fragments without LTAs show a marked influence of the Mg2+ concentration on enzyme activity 31). 

Glaser and Burger, using membrane preparations of several bacterial species and various nucleotide precursors, prepared in vitro a few kinds of teichoic acids which were identical with samples extracted from the cell walls of the studied strains. The following TA chain precursors were used cytidine diphosphate glycerol (CDP-... 

Teichoic Acids and Their Models Membrane Biopolymers with... 

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