Galactomannan antigen and preparation method thereof

Abstract

The invention relates to a preparation method of a galactomannan antigen. The method comprises the steps that breaking, centrifugation, alcohol precipitation, washing and drying are carried out on a living body rich in galactomannan, and galactomannan crude extract is obtained through separation; hydrazinolysis and hydrolysis are carried out on the obtained galactomannan crude extract in sequence; an enzyme is added to a hydrolysis product for enzymolysis, and the enzyme and small molecular substances in an enzymolysis product are removed; a product is purified through an ion exchange column, an affinity column and gel chromatography, and the pure galactomannan antigen is obtained; the obtained pure galactomannan antigen is identified. The galactomannan antigen obtained through the preparation method is high in purity, the inference of galactosamine, protein, miscellaneous sugar possibly included in the galactomannan crude extract is eliminated, and the preparation method can be used for preparing aspergillus fumigatus antibodies.

Description

technical field [0001] The invention relates to the field of antigen preparation, in particular to a galactomannan antigen and a preparation method thereof. Background technique [0002] Galactomannan (GM for short) exists in the cell walls of fungi (such as Aspergillus, Penicillium, etc.) and endosperm legumes (such as fenugreek, guar bean, carob, etc.), and is widely used in food and medical and clinical fields. [0003] At present, due to the extensive use of antibiotics and immune preparations, fungal infections are on the rise year by year, and Aspergillus, especially Aspergillus fumigatus, has gradually become an important pathogenic fungus clinically. Galactomannan, as the skeleton of Aspergillus cell wall, is also the secreted antigen of Aspergillus. Galactomannan antigen is considered to be the target of early diagnosis of invasive aspergillosis. Therefore, obtaining specific anti-galactomannan antibodies is of great significance for the diagnosis of aspergillosis...

AI Technical Summary

Problems solved by technology

However, when galactomannan is used as an antigen for preparing antibodies, the crude extract contains impurities such as glycosamines and proteins, which cannot meet the requirements for antibody preparation. In the prior art, the crude extract is also further purified For example, the Chinese invention patent application with the application number CN201110289099.8 discloses that the crude extract of galactomannan is subjected to ultrafiltration treatment, and proteins, miscellaneous sugars and glycoproteins less than a certain molecular weight are filtered out, thereby obtaining a purity of 90 % above galactomannan antigen

However, using this method to purify galactomannan can only remove impurities with a molecular weight significantly smaller than that of galactomannan. Sugar molecules cannot be filtered out

In addition, in the prior art, the crude extract is also purified by hydrazinolysis, hydrolysis or chromatography. However, this purification is mainly used for the characterization of the structure of galactomannan, and the purity of galactomannan cannot be guaranteed. And suitable molecular weight distribution, not conducive to industrial mass production

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