Inhibitor of activation of β-glucan recognition protein

A liquid reagent for measuring peptidoglycan comprising a body fluid of an insect and a polysaccharide having two or more β 1→3 linkages in which 10% or more of sugar residues of the polysaccharide have a substituent at the 6-position, whereby the polysaccharide inhibits a βGlucan recognition protein of the insect body fluid and peptidoglycans can activate the proPO cascade in thus obtained insect body fluid.

A two solution reaction process for measuring peptidoglycan, which comprises the steps of:

• reacting a sample solution with a reagent solution obtained by dissolving a polysaccharide having two or more β 1→3 linkages in which 10% or more of sugar residues of the polysaccharide have a substituent at the 6-position in a solvent and mixing the reagent solution with the sample solution containing body fluid of an insect to make them present together,
• measuring a reaction time required for the absorbance of the reaction solution to reach a predetermined threshold value, and
• calculating the peptidoglycan content of the sample from thus obtained reaction time and a calibration curve showing the relationship between peptidoglycan concentration and reaction times which have previously been obtained by use of standard solutions containing known concentrations of peptidoglycan by the same procedure as the case of sample.

A two solution reaction process for inhibiting the activation of βGlucan recognition protein, which comprises dissolving a polysaccharide having two or more β 1→3 linkages in which 10% or more of sugar residues of the polysaccharide have a substituent at the 6-position in a solvent solution and mixing the solvent solution containing the polysaccharide with a sample solution containing a body fluid of an insect, whereby the polysaccharide inhibits the βGlucan recognition protein of the insect body fluid and peptidoglycans can activate the proPO cascade in thus obtained insect body fluid.

A process for measuring peptidoglycan, which comprises reacting a sample with a reagent obtained by dissolving a polysaccharide having two or more β 1→3 linkages in which 10% or more of sugar residues of the polysaccharide have a substituent at the 6-position in a body fluid of an insect to make them present together or mixing a solution containing the polysaccharide with the body fluid,

• measuring a reaction time required for the absorbance of the reaction solution to reach a predetermined threshold value,
• calculating the peptidoglycan content of the sample from thus obtained reaction time and calibration curve showing the relationship between peptidoglycan concentration and reaction times which have previously been obtained by use of standard solutions containing known concentrations of peptidoglycan by the same procedure as the case of sample.

A process for inhibiting the activation of β-glucan recognition protein, which comprises dissolving a polysaccharide having two or more β 1→3 linkages in which 10% or more of sugar residues of the polysaccharide have a substituent at the 6-position in a body fluid of an insect to make them present together or mixing a solution containing a polysaccharide with the body fluid.