Unique poly(glycerophosphate) lipoteichoic acid and the glycolipids of a Streptococcus sp. closely related to Streptococcus pneumoniae

Abstract

The Streptococcus sp. studied here is closely related to Streptococcus pneumoniae with 98.6% 16S rRNA similarity and 65% DNA/DNA homology. We isolated the lipoteichoic acid and the membrane glycolipids whose structures were established using conventional procedures and NMR spectroscopy. The lipoteichoic acid contains a linear 1,3-linked poly(glycerophosphate) chain which is partly substituted with d-alanine ester and is phosphodiester-linked to O6 of b-d-Galf(133)acyl 2 Gro. This lipoteichoic acid is the first example in which a monohexosylglycerol serves as the glycolipid anchor; and with an average chain length of 10 glycerophosphate residues it is the shortest known to date. MS analysis, applied for the first time to a native acylated lipoteichoic acid, revealed a continuous increase in chain length from seven to 17 glycerophosphate residues with a maximum at 10, and allowed identification of the fatty acid combinations. Membrane glycolipids consistedIt is noteworthy that in lipoteichoic acid biosynthesis, Galfacyl 2 Gro, a less abundant membrane glycolipid, is selected as the lipid anchor. Despite the genetic relatedness to Streptococcus pneumoniae, the lipoteichoic acid structure is quite different to the complex structure of pneumococcal lipoteichoic acid [T. Behr et al. (1992) Eur. J. Biochem. 207, 1063±1075], thus providing an example that minor differences in DNA sequence exert major changes in macromolecular structure. In this study we isolated a poly(glycerophosphate)-LTA from a Streptococcus sp. that is closely related to Streptococcus pneumoniae (see Discussion). This LTA is noteworthy in two aspects: it is, on average, only 10 glycerophosphates in length and the glycolipid anchor is 3-O-(b-d-galactofuranosyl)-1,2-di-O-acyl-sn-glycerol. This monohexosyldiacylglycerol, a rare glycolipid in Gram-positive bacteria [11,12] also occurs among the membrane glycolipids of our strain. Analysis revealed that it is not the biosynthetic precursor of the other glycolipids because these are derived from 3-O-(a-d-glucopyranosyl)-1,2-di-O-acyl-sn-glycerol. E X P E R I M E N T A L P R O C E D U R E SBacterial strain and growth Streptococcus sp. DSM 8747, deposited at the Deutsche Sammlung von Mikroorganismen according to the Budapest treaty, is characterized taxonomically elsewhere. Bacteria were Eur.

A Continuum of Anionic Charge: Structures and Functions ofd-Alanyl-Teichoic Acids in Gram-Positive Bacteria

“…strain DSM 8747, which is closely related to S. pneumoniae (with phosphorylcholine TAs), contains type I LTA with an average chain length of 10 Gro-P units partially substituted by D-alanyl esters (417). The chain length distribution varies from 7 to 17, and the glycolipid anchor is a rare 3-O-(␤-D-galactofuranosyl)-1,2-diacylglycerol (417). Based on the side chain substituents of LTA, Bacillus strains/species are divided into group A and group B.…”

“…It was hypothesized that a specific glycerol phosphotransferase targets the glycolipid with a single Gro-P unit and that this modified glycolipid would serve as the growing point for the assembly of the poly(Gro-P) chain (161,272,417). In Streptococcus sp.…”

“…In Streptococcus sp. strain DSM 8747, the least abundant glycolipid (monohexosyldiacylglycerol) is selected of the four for the membrane anchor (417). Several short-chain D-alanyl-lipophilic LTAs that could participate in this targeting process have been described (71,287).…”

Both Hemopoietic and Resident Cells Are Required for MyD88-Dependent Pulmonary Inflammatory Response to Inhaled Endotoxin

“…Three days after washing and reculturing in fresh medium, the cell preparation contained a homogenous population of Ͼ95% macrophages. The BMDM were plated in 96-well microculture plates (at 10 5 cells per well) and stimulated with LPS (E. coli, serotype 055: B5, at 100 ng/ml) and lipoteichoic acid (LTA; Lunamed) at 10 g/ml (35). Cell supernatants were harvested after 18 -24 h of stimulation for TNF measurement and analyzed immediately or stored at Ϫ20°C.…”

Total synthesis of biologically active lipoteichoic acids

“…39,40 LTA-T ( Figure 4) comprises a linear (1-3)-linked poly(glycerophosphate) chain which is partly substituted with 2-O-D-alanyl residues; this part is phosphodiester linked to the 6-hydroxy group of 3-O-(β-Dgalactofuranosyl)-1,2-di-O-acyl-sn-glycerol; thus, LTA-T belongs to the type I LTA structures. LTA-T is interesting in two aspects: firstly it only contains ten glycerophosphates (GroP) in length with about three D-alanyl residues attached on average, which is the shortest hydrophilic GroP chains known by now; secondly the core of the lipid anchor contains a rare mono-hexosyl-1,2-diacyl-sn-glycerol glycolipid in Gram-positive bacteria.…”