Lipopolysaccharide-Binding Protein ELISA Kit (LBP)

INTENDED USE

Human LBP ELISA kit can measure concentrations of LBP (lipopolysaccharide-binding protein, LPS-binding protein) present is plasma, serum, biological fluids or tissue homogenate samples.

INTRODUCTION

Lipopolysaccharide (LPS)-binding protein (LBP) is an acute phase protein that binds the lipid A moiety of LPS, facilitating immune detection of Gram-negative bacteria. As a class of pathogen-associated molecular patterns (PAMPs) exposed on the outer membrane of these bacteria, LPS elicits potent inflammatory responses triggered by Toll-like receptor 4 (TLR4) signaling. By extracting individual LPS molecules from bacterial membranes and presenting them to immune cells, LBP enables sensitive detection of minute amounts of Gram-negative bacteria.

As an extracellular glycolipid-binding protein, it extracts individual LPS molecules from aggregated structures and bacterial cell walls through high-affinity binding to lipid A. This transports monomeric LPS to soluble or membrane-bound CD14, which then transfers LPS to the TLR4/MD2 receptor complex on immune cells. This catalyzes LPS detection at concentrations up to 1000 times lower than in the absence of LBP. Consequently, LBP drastically lowers the threshold for LPS-induced cell activation. However at very high LPS concentrations, LBP binding to CD14 is no longer required for cellular stimulation.

Once triggered by LPS-induced TLR4 signaling, inflammatory cascades stimulate further LBP production by hepatocytes as part of the acute phase response. This amplifies and sustains immune reactions against the invading pathogens. However uncontrolled responses can result in endotoxic shock highlighting the delicate balance between sufficient and excessive LBP activity. As Gram-negative infections constitute a major cause of sepsis, delineating mechanisms governing this system may uncover paths to temper inflammation during sepsis without compromising antibacterial defenses.

CONTENT

All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

• One 96-Well Plate: Pre-coated with anti-LBP antibody.
• Standards: Lyophilized recombinant.
• Sample/Standard Dilution Buffer.
• Biotinylated-labelled Antibody.
• Antibody Dilution Buffer.
• HRP-Streptavidin Conjugate (SABC).
• SABC Dilution Buffer.
• TMB Substrate.
• Wash Buffer (25x).
• Plate Sealer.
• Product Instructions.

TYPICAL RESULTS

For this LBP ELISA kit, it is recommended that a standard curve is generated for each assay carried out.

Standard Curve: 0, 31.25, 62.5, 125, 250, 500, 1000, 2000 pg/ml.
Reactivity: Human
Sensitivity: 18.75 pg/ml
Range: 31.25 – 2000 pg/ml
Principle: Sandwich, Double Antibody
Application: Research Use Only.

ASSAY CHARACTERISTICS

– Specificity: Highly specific for LBP, no cross reactivity or interference between LBP and analogues was detected.
– Recovery: Serum (91 – 101%), EDTA Plasma (88 – 97%), Heparin Plasma (87 – 105%).
– Linearity: Serum (85 – 100%), EDTA Plasma (82 – 98%), Heparin Plasma (82 – 100%).
– Precison Intra-Assay: CV < 8%
– Precison Inter-Assay: CV < 10%

REFERENCES

1. Lipopolysaccharide binding protein and CD14 in LPS dependent macrophage activation. Immunobiology. (1993) 187 (3-5): 227-32. Tobias P.S. and Ulevitch R.J.
2. Function of lipopolysaccharide (LPS)-binding protein (LBP) and CD14, the receptor for LPS/LBP complexes: a short review. Res Immunol. (1992) 143 (1): 11-5. Schumann R.R.
3. Lipopolysaccharide-binding protein and future Parkinson’s disease risk: a European prospective cohort. J Neuroinflammation. (2023) 20 (1): 170. Zhao Y., et al.

ADDITIONAL INFORMATION

• Full Name: Lipopolysaccharide-Binding Protein ELISA Kit (LBP)
• Reactivity: Human
• Sample Type: Plasma, Tissue Homogenates, Serum, Biological Fluids
• Sensitivity: 18.75 pg/ml

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