Lipopolysaccharides

Lipopolysaccharides - Names and Identifiers

Name	Lipopolysaccharides
Synonyms	Lipopolysaccharides LIPOPOLYSACCHARIDE FROM ESCHERICHIA COLI

Lipopolysaccharides - Physico-chemical Properties

Solubility	5 mg/mlWater;: Soluble in water (10 mg/ml) or cell culture medium (1 mg/ml) to produce turbid yellowish solution, dissolved in salt solution by vortex oscillation and heating to 70-80 ℃ can obtain a higher concentration of LPS solution (20 mg/ml). 1.
Appearance	lyophilized powder
Storage Condition	2-8°C

Lipopolysaccharides - Risk and Safety

Hazard Symbols	Xn - Harmful
WGK Germany	3

Lipopolysaccharides - Introduction

Lipopolysaccharide, English name Lipopolysaccharides, or LPS for short, is a unique component in the cell wall of Gram-negative bacteria. It is located in the outermost layer of the cell wall and exposed to the cell surface of non-capsular bacteria, which is beneficial to maintain the integrity of the outer membrane of the cell. Protect bacteria from the damage of bile salts and lipid antibiotics. Structurally, lipopolysaccharide is composed of lipid A, core polysaccharide and O-polysaccharide side chain. Among them, lipid-like A is the main component of bacterial endotoxin, which determines its toxicity. The side chain of O-polysaccharide is highly variable among different bacteria, and the specificity determines the serotype of the bacteria. LPS can cause immune stimulation cascade and toxic pathophysiological activities of the body, including the release of endotoxin to cause septic shock, resulting in peripheral vascular collapse. Clinically, meningitis is often diagnosed by detecting the presence of LPS. It is the close relationship between LPS and the body's immune function. Life science research often extracts LPS for related research, such as clarifying the structure, metabolism, immunology, physiology, toxicity, and biosynthetic pathways of LPS; inducing growth promoting factors such as interleukin Synthesis and secretion; animal models of induced disease research such as inflammation and acute lung injury. LPS can be reacted with FITC, TRITC or 2,4,6-trinitrobenzene sulfonic acid (TNBSA) to obtain FITC, TRITC or TNP-labeled LPS, which is mainly used for the study of immune response of thymus-independent B cells to bacterial LPS.. LPS can be prepared by TCA, phenol, phenol-chloroform-petroleum ether and other methods, the last method is crude extraction. LPS obtained by TCA and phenol extraction are similar in structure, electrophoresis pattern and endotoxin level, except that it contains different nucleic acid and protein residues. LPS obtained by TCA method contains about 2% RNA and 10% denatured protein. LPS extracted by phenol method contains up to 60% RNA and less than 1% protein. Gel filtration chromatography removes residual proteins from phenol-extracted LPS, but still leaves about 10-20% of nucleic acids. Further purification by ion exchange chromatography can obtain LPS of <1% protein and <1% RNA. This product is derived from serotype Escherichia coli O55:B5 and extracted by benzene method. Its endotoxin level is not less than 500,000 EU (endotoxin units)/mg. After analysis, 1ng is equivalent to 0.5EU (horseshoe crab reagent method) and 10EU (chromogenic method). LPS O55:B5 can be used to stimulate the activity of human peritoneal macrophages (1ng/ml) and horse peritoneal macrophages (1-100ng/ml).

Last Update：2022-10-16 17:31:03

Lipopolysaccharides - Uses and synthesis methods

overview

lipopolysaccharide, a thick layer (8 ~ 10nm) of substance located in the outermost layer of the cell wall of gram-negative bacteria, is formed by covalent binding of lipid A, core polysaccharide and O-specific side chain 3 parts. Among them, lipid A is composed of 2 N-acetylglucosamine and 5 saturated long-chain fatty acids. The core polysaccharide is divided into two parts: the inner core region and the outer core region, the inner core region consists of 3 2-keto-3 deoxyoctanoic acids (KDO) and 3 L-glycerol-D-mannoheptose (Hep), the outer core region consists of 5 hexoses, and the O-specific side chain consists of multiple tetrahexose units; it not only has good decontamination, emulsification, washing, dispersion, solubilization, penetration, foaming, viscosity adjustment, anti-aging, anti-crystallization, anti-static and other properties, but also has non-toxic, odorless, non-polluting, non-irritating, Easy to biodegrade and other excellent characteristics, but also has antibacterial, fresh-keeping, antiviral, anti-tumor, removal of ester garbage in the body and other pharmacological effects and immune functions; therefore, it is widely used in food, medicine, chemical industry, cosmetics, detergent, textile, agriculture and animal husbandry industries.

chemical composition

It is formed by covalent binding of lipid A, core polysaccharide and O-specific side chain 3 parts. Lipid A is composed of 2 N-acetylglucosamine and 5 saturated long-chain fatty acids. The core polysaccharide is divided into two parts: the inner core region and the outer core region. The inner core region consists of 3 2-keto -3 deoxyoctanoic acids (KDO) and 3 L-glycerol-D-mannoheptose (Hep), and the outer core region consists of 5 hexoses. O-specific side chains are composed of multiple tetrahexose units. It contains lipid 36.7%, total sugar 47.7%, total nitrogen 1.02%, total phosphorus 1.23% and protein 6.38%.

Pharmacological action

1. After proper plant lipopolysaccharide enters animals or humans, it can enhance the body's non-specific immunity in a short time, which plays a great role in improving the body's ability to resist diseases.

2. Lipopolysaccharide can also resist blood coagulation, anti-thrombosis, reduce cardiovascular system diseases, lower blood sugar and other health functions.

3. The lipopolysaccharide in tea has the effect of preventing radiation, and it also has the effect of improving hematopoietic function and protecting blood phase.

biological action

1. Fever reaction.

2. leukocyte response.

3. endotoxemia and endotoxin shock.

4. Disseminated intravascular coagulation.

5. Others: A small amount of LPS can activate B cells and produce polyclonal antibodies; Promote the maturation of T cells; Activate the activity of macrophages and NK cells; Induce immune regulatory factors such as interferon, tumor necrosis factor (TNF), colony stimulating factor (CSF), interleukin -6, etc.

features

1. is the material basis of Gram-negative bacterial endotoxin.

2. Increase the concentration of magnesium and calcium ions on the cell surface.

3. Because of its molecular variability, it determines the diversity of cell surface antigenic determinants.

4. It is a specific adsorption receptor for several phages.

Last Update：2024-04-10 22:29:15