The Structures of Myocotrienins I. and II,a Novel Class of Ansamycin Antibiotic |
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Authors: | Masanori Sugita Kazuo Furihata Haruo Seto Noboru Ōtake Tetsuo Sasaki |
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Affiliation: | 1. Institute of Applied Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan;2. Central Research Laboratory, Nisshin Flour Milling Co., Ltd., Ohi, Iruma-gun, Saitama 354, Japan |
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Abstract: | Endopolygalacturonase I [EC 3.2.1.15], the major component of endopolygalacturonases causing silver-leaf symptoms, was purified from culture liquids of Stereum purpureum by column chromatographies on CM-52 and Sephadex G-100. The purified enzyme was homogeneous on Polyacrylamide gel electrophoresis and ultracentrifugation. The sedimentation coefficient (S20,W) was determined to be 3.21 S, and the molecular weight was estimated to be 40,000 by gel filtration, 41,000 by SDS-polyacrylamide gel electrophoresis and 44,000 by sedimentation equilibrium. The enzyme had an isoelectric point of pH 8.5. The optimal pH of the enzyme was 3.5 for trigalacturonic acid, 4.0 for tetragalacturonic acid, and 4.5 for pectic acid. The enzyme was stable in the range of pH 4.0 to 9.0 and up to 70%C for 30 min. The amount of the enzyme which was required to induce silver-leaf symptoms on apple trees was 20 μg/tree. |
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Keywords: | royal jelly glycoprotein N-glycan Thomsen-Friedenreich antigen (Galβ1-3GalNAc) β1-3 galactosyltransferase Apis mellifera |
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