Isolation and Characterization of a Novel Immunomodulatory α-Glucan−Protein Complex from the Mycelium ofTricholoma matsutakein Basidiomycetes

Abstract

Tricholoma matsutake, a high-class edible mushroom in Japan, has been reported to have excellent biological activities, but difficulty in cultivating the fruit bodies and limited bulk availability have restricted detailed studies. We have developed a method of culturing in tanks, enabling the bulk supply of the mycelia. The preparation (CM6271) exerts modulative effects on the immune competence of mice and rats. In this study, a sodium hydroxide extract of CM6271 was defatted followed by fractionation with a combination of ion exchange chromatography and gel filtration in order to identify the components involved in the expression of the activity, and a single peak fraction (MPG-1) was obtained with reversed phase chromatography. MPG-1 was a glycoprotein (sugar:protein ratio, 94.3:5.7) with a relative molecular mass of 360 kDa, and the sugar moiety contained about 90% glucose. NMR spectra and methylation analysis revealed that the alpha-1,4-linkage was the predominant glucan linkage with alpha-1,6- and alpha-1,2-linkages in the minority. The amino acid composition in the protein moiety was rich in glutamine, alanine, asparagine, leucine, glycine, valine, serine, threonine, isoleucine, and proline. MPG-1 was resistant to degradation with amylase or protease. The oral administration of MPG-1 promoted, in a dose-dependent manner, the recovery of the mouse natural killer cell activity and serum IL-12 level that had been reduced by the loading of restraint stress. The dose of MPG-1 (25 mg/kg) required for the expression of the effect decreases to 1/12 of that of CM6271 (300 mg/kg). Furthermore, MPG-1 formed a complex with TGF-beta1 in vitro, modulating the biological activity of TGF-beta1 by binding to its active form. These results indicate that the mycelium of T. matsutake contains a novel alpha-glucan-protein complex with immunomodulatory activities.

Effects of α-glucans from Agaricus bisporus on ex vivo cytokine production by LPS and PHA-stimulated PBMCs; a placebo-controlled study in slightly hypercholesterolemic subjects

“…In contrast, in mice an elevated IFNg production by splenocytes after dietary supplementation with A. bisporus has been reported (Wu et al, 2007). Moreover, the consumption of an a-glucan protein complex (94.3% sugar) from another fungal source (Tricholoma matsutake) recovered the stress-induced decrease in IL-12 serum concentration in mice (Hoshi et al, 2005). This suggests that a-glucans could have in vivo effects on Th1 cytokines, at least in mice.…”

Biosynthesis, Purification and Biotechnological Use of Exopolysaccharides Produced by Lactic Acid Bacteria

“…In an in vitro model the compound formed a complex with the active form of TGF-β1. These results indicate that the mycelium contains a novel α-glucan-protein complex with immunomodulatory effect (Hoshi et al, 2005).…”

Extract of the mycelium of T. matsutake inhibits elastase activity and TPA-induced MMP-1 expression in human fibroblasts

“…The mycelium of T. matsutake has also been reported to have excellent biological activities; the extract from the natural biomaterial of this mushroom is rich in polysaccharides, such as β-glucan. Moreover, β-glucan is presently available as an ingredient in cosmetic formulations and is found in extracts from mushroom, yeasts, various fungi, cereals and seaweed (18). The extract of the mycelium of T. matsutake also has strongly bioactive properties, exerting antioxidant, cholesterol-lowering, heart disease prevention, and antitumoral, anti-aging, anti-wrinkle and anti-acne effects (16,19,20).…”