Glycobiology Advance Access published online on May 1, 2008
Glycobiology, doi:10.1093/glycob/cwn036
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Structural characterization of glycosylinositolphospholipids with a blood group type B sugar unit from the edible mushroom, Hypsizygus marmoreus
1 Department of Chemistry, Faculty of Liberal Arts and Education, Shiga University, Hiratsu, Otsu, Shiga 520-0862, Japan
2 Department of Applied Molecular Biology, Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
3 Kyoritsu College of Pharmacy, 1-5-30, Shibakoen, Minato-ku, Tokyo 105-8512, Japan
4 Department of Medicine, Division of Nephrology, The University of Tennessee, Court Avenue, Memphis TN 38163, USA
* To whom correspondence should be addressed: Tel/Fax: +81-77-537-7728 E-mail: itonori{at}sue.shiga-u.ac.jp
Received on February 1, 2008; accepted on April 25, 2008
Edible fungi, mushrooms, are a popular food in Japan and over fifteen cultured mushroom species are available at the food markets. Recently, constituents or ingredients of edible mushrooms have drawn attention because possibilities have been seen for their medical usage. Mycoglycolipids (Basidiolipids) of higher mushrooms have been characterized as glycosylinositolphosphoceramides, having a common core structure of Man
1–2Ins1-[PO4]-Cer and extension of Man, Gal and/or Fuc sugar moieties. Seven mycoglycolipids were purified from the edible mushroom Hypsizygus marmoreus by successive column chromatography on ion exchange Sephadex (DEAE-Sephadex) and silicic acid (Iatrobeads). Their structures were characterized to be Ins1-[PO4]-Cer (AGL0), Man1–2Ins1-[PO4]-Cer (AGL1), Galβ1–6Man1–2Ins1-[PO4]-Cer (AGL2), Fuc1–2Galβ1–6Man1–2Ins1-[PO4]-Cer (AGL3), Gal1–3(Fuc1–2)Galβ1–6Man1–2Ins1-[PO4]-Cer (AGL4), Gal1–2Gal1–3(Fuc1–2)Galβ1–6Man1–2Ins1-[PO4]-Cer (AGL5) and Gal1–2Gal1–2Gal1–3(Fuc1–2)Galβ1–6Man1–2Ins1-[PO4]-Cer (AGL6) by sugar compositional analysis, methylation analysis, periodate oxidation, partial acid hydrolysis, enzymatic hydrolysis, immunochemical analysis, gas-liquid chromatography (GC), gas chromatograph-mass spectrometry (GC-MS), matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 1H-nuclear magnetic resonance spectroscopy (NMR). Ceramide constituents of their mycoglycolipids were composed of phytosphingosine as the sole sphingoid, and mainly 2-hydroxy C22:0 and C24:0 acids as the fatty acids.
By immunochemical detection, the terminal structure of AGL4, Gal1–3(Fuc1–2)Galβ-, was shown to have blood group type B activity. Gal1–2 and its repeating sequence in AGL5 and AGL6 are novel structures on the non-reducing sugar end in mycoglycolipids. These two mycoglycolipids in H. marmoreus distinguish it from other basidiomycetes.
Key words: blood group / glycosphingolipid / Hypsizygus marmoreus / mushroom / mycoglycolipid
** Current address: Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA