Application of Biosensor Technology to Screening of Anti-endotoxin Materials in Radix Paeoniae Rubra / 中国药房

OBJECTIVE:To apply the biosensor technology to screening of the best method to extract and separate anti-endotoxin effective materials in Radix Paeoniae rubra.METHODS:The affinities of samples extracted by three different methods binding to lipopolysaccride(LPS)were determined with biosensor technology.Extracted materials were incubated with0.25EU/ml endotoxin for determination of change of binding activity.RESULTS:Material extracted by water showed high binding capa?bility with LPS,after incubation with endotoxin,still had highly effective anti-endotoxin component;1∶40diluted water extract could neutralize78.1%endotoxin.Determination results by biosensor technology and traditional limulus reagent showed no dif?ference.CONCLUSION:Water extraction could obtain more anti-endotoxin effective materials.Compared with traditional methods,biosensor technology is a fast,highly effective,direct and accurate method.

Study of Isolating Anti-Endotoxin Monomer Component from Radix Paeoniae Rubra Biosensor by Biosensor Technique / 中国药房

OBJECTIVE:To isolate anti-endotoxin monomer component from Radix Paeoniae Rubra by means of biosen?sor technique.METHODS:The surface of biosensor cuvette was embedded by Lipid A;the screening target was established,tracking the silica gel column chromatogram and the binding ability of effluent component from HPLC with Lipid A with the ultraviolet scan result of the reclaimed material from biosensor as reference;anti-endotoxin monomer component was isolated;the component of monomer and the synthetic action of extrinsic lipopolysaccharides were also assayed by LAL test method.RESULTS:Components binding to Lipid A was reclaimed from cuvetee by biosensor technique,with the wavelength of UV absorption peak at194nm,215nm and275nm respectively.Anti-endotoxin monomers of higher binding activity with Lipid A isolated by HPLC method were1,2,3,4,6—O—pentagalloyl—?—D—glucose(PGG).PGG at concentration of8,4,2?g/ml respectively neutralized68.8%,43.7%and31.4%of LPS at an activity of0.1EU/ml respectively.CONCLUSION:It is fea?sible to isolate anti-endotoxin monomer component from Radix Paeoniae Rubra by means of biosensor technique,which is a fast,accurate and efficient and can be used to isolate anti-endotoxin monomer component from Radix Paeoniae Rubra on a large scale.

AFFINITIES OF PEPTIDE (BNEP) MIMICKING BACTERICIDALITY/PERMEABILITY-INCREASING PROTEIN FOR LIPOPOLYSACCHARIDE AND Lipid A BY BIOSENSOR TECHNOLOGY / 解放军医学杂志

To explore the mechamisms of bactericidal neutralizing endotoxin peptide(BNEP), a synthetic peptide mimicking bactericidality/permeability-increasing protein (BPI). The affinities of BNEP for LPS and Lipid A were determined with biosensor technology, and the ability of BNEP neutralizing LPS in vitro was tested by quantitative limulus amoebocyte lysate assay. The results showed that BNEP had high affinities for both LPS and Lipid A. The Kd value for LPS was at the level between 25.8 and 48.8nmol/L and for Lipid A from 11.8 to 21.8nmol/L. When 8?g/ml of BNEP was used, it could completely neutralize the concentration of 2ng/ml of LPS in vitro. It is concluded that BNEP has high binding affinities for both LPS and Lipid A. Our results also suggest that the binding site of LPS is at the glucosaminyl-?1'-6-glucosamine disaccharide of Lipid A. The binding activity of BNEP for LPS is in accord with its neutralizing activity for LPS.