Development of an Enzyme-Linked Immunosorbent Assay To Detect an Immunomodulatory α-d-Glucan–Protein Complex, MPG-1, in Basidiomycete Tricholoma matsutake and Related Processed Foods

• Published in: Journal of agricultural and food chemistry Vol. 55; no. 21; pp. 8508 - 8515
• Main Authors: Hoshi, Hirotaka, Yagi, Yoko, Matsunaga, Kenichi, Ishihara, Yoko, Yasuhara, Tadashi
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 17.10.2007
• Subjects: alpha-D-glucan-protein complex; Animals; Basidiomycetes; Basidiomycota - chemistry; bioactive constituent; Biological and medical sciences; edible fungi; enzyme-linked immunosorbent assay; enzyme-linked immunosorbent assay (ELISA); Enzyme-Linked Immunosorbent Assay - methods; Female; Food industries; fruiting bodies; Fruiting Bodies, Fungal - chemistry; Fundamental and applied biological sciences. Psychology; Fungal Proteins - analysis; Fungal Proteins - immunology; glucans; Glucans - analysis; Glucans - immunology; glycoproteins; Immunologic Factors - analysis; immunomodulatory α-d-glucan–protein complex; immunosuppressive agents; MPG-1; mushrooms; mycelium; Mycelium - chemistry; Peptides; processed foods; Rabbits; Sensitivity and Specificity; soups; Tricholoma; Tricholoma matsutake; α-d-glucan; MPG-1; Tricholoma matsutake; enzyme-linked immunosorbent assay (ELISA); α-d-glucan; immunomodulatory α-d-glucan–protein complex; immunomodulatory α-D-glucan-protein complex; Immunomodulation; Basidiomycetes; Enzyme immunoassay; Protein; Fungi; Assay; Glucan; α-D-glucan; Development; Processed food; Polysaccharide; ELISA assay; Thallophyta
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf071809z

We previously isolated a novel immunomodulatory α-(1,4)(1,6)(1,2)-d-glucan–protein complex (MPG-1) from mycelia of Tricholoma matsutake in basidiomycetes. In the present study, we raised a polyclonal antibody by immunizing rabbits with MPG-1 and constructed a sandwich enzyme-linked immunosorbent assay (ELISA) system to examine the distribution of MPG-1 among edible mushrooms and related processed foods. The system detected MPG-1 quantitatively at concentrations of more than 10 ng/mL, with a coefficient of variation of less than 10% by intra-assay and interassay precision. Analysis with the system of chemically modified MPG-1 suggested that the sugar moiety was mainly involved in the detection. The system detected MPG-1 in the extracts of the fruiting bodies of T. matsutake but not in those of 34 other basidiomycete species. Moreover, a significant amount of MPG-1 was detected in the extracts of their cultured mycelia. The antigenic structure of MPG-1 was relatively stable in terms of pH and temperature. MPG-1 was detected in processed foods supplemented with T. matsutake. These results suggest that MPG-1 is distributed predominantly in T. matsutake species and that the ELISA system can detect it in processed foods supplemented with T. matsutake.