The aqueous layer was isolated from
Leptospira interrogans serovar
canicola strain Moulton by the hot phenol-water method. After ultracentrifugation, the precipitate was designated as lipopolysaccharide-like substance (LLS) fraction and the chemical composition was compared with that of bacterial LPS. The LLS fraction consists of 35.2% carbohydrate, 3.8% amino sugar, 36.4% lipid, 15.2% protein, and 0.3% phosphorus. Neutral sugars were detected as rhamnose, arabinose, xylose, 4-
O-methylmannose, mannose, galactose, and a small amount of erythrose, fucose and glucose by gas-liquid chromatography (GLC), but 2-keto-3-deoxyoctonic acid was not detected in the LLS by thiobarbituric acid test and high voltage paper electrophoresis. Fatty acids detected by GLC were decanoic acid (C10:0), dodecanoic acid (C12:0), dodecenoic acid (C12:1), tridecenoic acid (C13:1), tetradecanoic acid (C14:0), hexadecanoic acid (C16:0), hexadecenoic acid (C16:1), and octadecenoic acid (C18:1). With SDS-polyacrylamide gel electrophoresis, bacterial LPS showed many orderly bands, while the banding pattern of the leptospiral LLS was very simple. These findings demonstrate that the physicochemical properties and chemical composition of LLS fraction from
Leptospira are different from those of LPS extracted from gram-negative bacteria such as
Enterobacteriaceae, and suggesting that
Leptospira has no typical LPS.
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