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Extracellular culture filtrates from ligninolytic cultures of the lignin-degrading basidiomycete Lentinula (syn. Lentinus) edodes (Berk.) Pegler contained one major peroxidase when grown on a commercial oak-wood substrate. The peroxidase was purified by polyethylenimine clarification, anion-exchange chromatography, and hydrophobic-interaction HPLC. The enzyme (MnP1) was a heme-iron protein with an apparent molecular weight of 44,600 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels and an isoelectric point of pH 3.2. The native enzyme had an absorption maximum at 407 nm, which shifted to 420 nm upon H2O2 addition. The pyridine-hemochrome-absorption spectrum indicated that one heme group was present per enzyme as protoporphyrin IX. N-Terminal amino acid sequencing showed that MnP1 had higher sequence homology with manganese peroxidases than with lignin peroxidases reported from Phanerochaete chrysosporium. L. edodes MnP1 was capable of oxidizing lignin and lignin-model compounds in the presence of manganese and H2O2.

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The primary structure of a third H2B histone isolated from sperm of the sea urchin Parechinus angulosus has been determined. H2B(3, consists of a polypeptide chain of the following 148 amino acid residue5 : Pro-Arg-Ser-Pro- A third protein has now been identified in the complement of H2B histones of animals of the same sea urchin species. The amino acid sequence of this histone H2B(3) Parerhinus is reported. MATERIALS AND METHODS Purification of HistonesHistone H2B(3) was purified by selective extraction [3], gel exclusion chromatography on Biogel P60, and ion-exchange chromatography on carboxymethyl-cellulose (CM-cellulose) as previously described for the other histone H2B variants. The yields from 100 g wet packed sperm were: 0.7 g (histone H1) in the perchloric acid extract, 1.7 g (histones H4, H3, H2A) in the 80% ethanol/0.25 M HC1 extract and 1.0 g (histone H2B, H1 and non-histone proteins) in the 0.25 M HCl extract; about 0.5 g of H2B mixture (Fig. 1) was obtained from the 0.25 M HCl extract after Biogel P60 fractionation. The yield of histone H2B was 14.7% of the total histones extracted. The yield of histone H2B variants from a typical CMcellulose run is shown in Fig. 2 B.