STUDIES ON THE RELATIONSHIP BETWEEN GLYCEROPHOSPHOGLYCOLIPIDS AND LIPOTEICHOIC ACIDS .4. TRIGALACTOSYLGLYCEROPHOSPHO-ACYLKOJIBIOSYLDIACYL-GLYCEROL AND RELATED-COMPOUNDS FROM STREPTOCOCCUS-LACTIS KIEL 42172

Streptococcus lactis Kiel 42172 contains at least six unusually polar glycerophosphoglycolipids. The predominant one was composed of d-ga1actose, d-glucose, glycerol, acyi groups and phosphorus in a molar ratio of approx. 3: 2: 2: 3: 1. By analysis of the breakdown products of HF hydrolysis and Smith-degradation the structure was established to be [Galp(α1 → 6)Galp(α1 → 3)-sn-glycero(2 ← 1αGalp)-1-phospho] → 6Glcp(α1 → 2), acyl → Glcp(α1 → 3)acyl2Gro. By HF hydrolysis the other compounds were shown to be in the main also derivatives of GroP→-6Glc(α1→ 2), acyl → 6Glc(α1 → 3)acyl2Gro but they released as water-soluble glycosides Gal(α1 → 2)Gro, Gal(α1 → 3)Gro, Gal(α1 → 3)Gro(2 ← 1αGal), Gal(α1 → 6)Gal(α1 → 3)Gro and Gal(α1 → 6)Gal(α1 → 6)Gal(α1 → 3)Gro(2 ← 1αGal), respectively. In the lipid extract Glc(α1 → 2), acyl → 6Glc(α1 → 3)acyl2Gro and GroP → 6Glc(α1 →2), acyl → 6Glc(α1 → 3)acyl2Gro were a1so observed. This set of compounds is proposed to constitute a biosynthetic series reflecting the individua1 steps in the synthesis of the lipoteichoic acid of Streptococcus lactis Kiel 42172 which is made up by the same lipid anchor and a non-classical poly(ga1abiosyl, ga1actosyl glycerophosphate)-chain (Koch H.U. and Fischer W. (1978) Biochemistry 17, 5275-5281). © 1979.