1. Structure
    Inner core  Outer core 

2. Biosynthesis

3. Function

4. See also

5. References

Structure

The core domain always contains an oligosaccharide component which attaches directly to lipid A and commonly contains sugars such as heptose and 3-deoxy-D-mannooctulosonic acid (also known as KDO, keto-deoxyoctulosonate).^[2] The LPS Cores of many bacteria also contain non-carbohydrate components, such as phosphate, amino acids, and ethanolamine substituents.

Many core structures have been described in the literature, this description is based on the traditional general structure (as found in enteric bacteria and Pseudomonas). See the figure above for an overview of the structure found in E. coli R1.

Inner core

The "base" of the inner core is 1–3 KDO residues. The last KDO is often modified with a phosphate or ethanolamine group. From the KDOs, there are attached 2–3 heptoses (i.e. L-glycero-D-mannoheptulose) that are usually phosphorylated. These KDO and heptoses comprise the "inner core".

The ketosidic bond between KDO and lipid A (α2→6) is especially susceptible to acid cleavage. LPS researchers use a weak acid treatment to separate the lipid and polysaccharide portions of LPS.

An LPS molecule that includes only a lipid A and an inner core (or less. See example) is referred to as "deep-rough LPS".

Outer core

The outer core is made of hexose residues that are attached to the last heptose residue in the inner core. Hexoses often found in the outer core include: D-glucose, D-mannose, D-galactose, etc.. There is usually at least three hexoses bound β1→3, with the O antigen being ligated to the third hexose. Other hexose are often found attached to the outer core, branching from the main oligomer.

LPS that include lipid A and a complete core oligosaccharide (inner and outer) is referred to as "rough LPS."

Biosynthesis

Function

Mechanism of how the core oligosaccharide of lipopolysaccharide affect the membrane behavior is not well understood.

See also

• Endotoxin

References

• SteadiCam
• Steadier Footing
• Steading of the Hill Giant Chief
• Steadman Marlin
• Steadman (name)
• Steadman Sanford
• Steadman Shealy
• Steadman S. Shealy
• Steadman Upham
• Steadman Vincent Sanford
• Steadman V. Sanford
• St. Eadsin
• Steady, As She Goes
• Steady, as She Goes
• Steady As She Goes
• Steady, As She Goes/Store Bought Bones
• Steady as She Goes (Voodoo Glow Skulls album)
• Steady Bootleggin'
• Steady Brook
• Steady & Co.
• Steady diet of nothing
• Steady Eddy
• Steady Groovin'
• Steady Ground
• Steady Mobbin' (Ice Cube song)