Characterization of ribonucleases from culture medium of Lentinus edodes.
Lentinus edodes (shiitake) cultivated in potato dextrose medium produced five RNases in the culture filtrate. The two major RNases (RNase Le37 and RNase Le45) were highly purified and their molecular masses, base specificities, N-terminal amino acid sequences, and amino acid compositions were analyzed and compared to RNase Le2 isolated from the fruit bodies of the same mushroom. RNase Le37 and RNase Le45 are base non-specific and adenylic acid preferential RNases like RNase Le2 and their N-terminal sequences are very similar to RNase Le2, but they are glycoproteins and their amino acid compositions are significantly different from that of RNase Le2. In addition to these enzymes, a guanylic acid-specific RNase with a molecular mass 13 kDa was partially purified. Since RNase Le2, which has very similar N-terminal sequence to RNase Le37 and RNase Le45, was not excreted from the mycelia, the analysis of the structures of these two excreted RNase may shade a light on the mechanism of excretion of RNases in this organism.
Department of Microbiology, College of Pharmacy, Nihon University, Chiba, Japan.
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H
Kobayasi
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Imanaka
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N
Inokuchi
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T
Koyama
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Irie
D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D004591:Electrophoresis, Polyacrylamide Gel; D006595:Hexosamines / Q000032:analysis; D020074:Lentinula / Q000737:chemistry / Q000201:enzymology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012331:RNA, Fungal / Q000032:analysis / Q000737:chemistry; D012260:Ribonucleases / Q000737:chemistry* / Q000302:isolation & purification; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D015003:Yeasts / Q000235:genetics
D000596:Amino Acids; D002241:Carbohydrates; D003470:Culture Media; D006595:Hexosamines; D012331:RNA, Fungal; D012260:Ribonucleases