Structure of the Alkali-Insoluble Skeletal Glucan of Lentinus edodes

Abstract

An alkali-insoluble core material was isolated from the fruit bodies of Lentinus edodes after exhaustive extraction with 24% NaOH at 5 degrees C. This material consists mainly of glucan which is closely associated with chitin. Methylation analysis has shown that the glucan part of the core material (skeletal glucan) has a highly branched structure with 1,6 and 1,3 linkages in a molar ratio of 2 : 1. Stepwise enzymatic hydrolysis with basidiomycete sp. QM 806 beta-1,3-glucanase has indicated the heterogeneity of the skeletal glucan. The outer part of the skeletal glucan seems to be composed mainly of beta-1,3 and beta-1,6 glucoside linkages and has a close structural similarity to lentinan, a water-soluble beta-glucan from L. edodes. The middle part of the skeletal glucan appears to be composed mainly of beta-1,6 glucoside linkages. The innermost part of the skeletal glucan is a highly branched glucan with beta-1,6 and beta-1,3 linkages. Probably, it is associated with chitin and a small amount of amino acid polymer.

Lentinula edodes tlg1 Encodes a Thaumatin-Like Protein That Is Involved in Lentinan Degradation and Fruiting Body Senescence

“…One of these roles is perhaps their propensity to function as antifungal agents. L. edodes TLG1 degrades lentinan, a b-1,3-glucan found in its own cell wall (Shida et al, 1981) and thus may play a role in cell wall degradation. Increasing endo-glucanase activity (Fig.…”

“…The cell walls of filamentous fungi have been investigated in several species of basidiomycota, including Schizophyllum commune (Wessels et al, 1972), Agaricus bisporus (Mol and Wessels, 1990), Coprinus cinereus (Bottom and Siehr, 1979), and Lentinula edodes (Shida et al, 1981). These reports have indicated that the major components of the cell wall are chitin and b-1,3-glucan with b-1,6-linked branches.…”

Senescence of the Lentinula edodes Fruiting Body After Harvesting

“…The cell wall of L. edodes is constructed of several polysaccharides, such as β-1,3-glucan, β-1,6-glucan, chitin, and chitosan (Shida et al 1981). Thus, β-1,3-glucanase, β-1,6-glucanase, chitinase, chitosanase are involved in cell wall degradation after harvesting.…”

Two Cell Wall β-d-Glucans fromNeurospora crassa

“…It is well known that skeletal glucans from the fruit bodies of some Basidiomycetes, such as Schizophyllum commune 8 ) or Lentinus edodes 27 ) are very resistant to solubilization. However, the sructures of these glucans are much more complicated.…”