Yoshitake Tanaka

Release of oligosaccharides possessing reducing-end N-acetylgalactosamine from mucus glycoprotein in Streptomyces sp. OH-11242 culture medium through action of endo-type glycosidase

A crude enzyme preparation from a culture medium of Streptomyces sp. OH-11242 contained endo-alpha-N-acetylgalactosaminidase activity. The activity could be induced by the addition of purified porcine gastric mucin to the culture medium. Oligosaccharides corresponding to approximately 2-14 glucose units were detected in the culture medium and also in an incubated reaction mixture of crude enzyme preparation and mucus glycoprotein. The resulting product with N-acetylgalactosamine at the reducing terminal implied the presence of a new type of endo-glycosidase liberating not only Gal beta 1-3GalNAc but also other larger oligosaccharides by hydrolysis of the O-glycosidic linkage between GalNAc and Ser (Thr).

Phthoxazolin A, a specific inhibitor of cellulose biosynthesis from microbial origin. II. Isolation, physico-chemical properties, and structural elucidation.

Phthoxazolin A is a new inhibitor of cellulose biosynthesis produces by Streptomyces sp. OM-5714. The active compound was isolated, and the structure was elucidated by spectrometric analyses.

Screening and fermentation of endo-α-N-acetylgalactosaminidase S, a mucin-hydrolyzing enzyme from Streptomyces acting on the GalNAc-O-Ser (Thr) linkage

Abstract Soil microorganisms were examined for their ability to grow on porcine gastric mucin as a sole source of carbon and energy. Streptomyces sp. OH-11242 thus selected was found to produce endo-α- N -acetylgalactosaminidase (endo-GalNAc-ase S), together with several mucin-degrading glycosidases. Endo-GalNAc-ase S is a new enzyme capable of hydrolyzing the innermost GalNAc- O -Ser (Thr) linkage of the mucin molecule. Studies on the fermentation conditions necessary for its production revealed that the enzyme was induced by mucin but the induction was inhibited by glucose and other easily assimilable carbon sources, as well as by complex nitrogen sources. Addition of palmitate, λ-carrageenan, or crude mucin to a mucin-based production medium enhanced enzyme production and mycelial growth. When the initial mucin concentration of the production medium was increased, the maximum titer of endo-GalNAc-ase S produced in the culture both also increased, while the cultivation time giving the peak enzyme titer was prolonged. As a result of the studies, increased and reproducible production of endo-GalNAc-ase S was achieved, reaching 42 units/ml in a 100-ml culture and 31 units/ml in an 800-ml culture with 2 and 1.5% purified mucin, respectively, as the major carbon source.

Analysis of porcine gastric mucus glycoprotein added to a culture medium of Streptomyces sp. OH-11242 as the only source of carbon.

1. In the process of obtaining the degradation enzymes of mucus glycoprotein, porcine gastric mucus glycoprotein (PGM), added as the only source of carbon, was removed from the culture medium of Streptomyces sp. OH-11242 [Iwase et al. (1988) Biochem. biophys. Res. Commun. 151, 422-428] and analysed. 2. The amino acid and carbohydrate compositions of porcine gastric mucus glycoprotein (PGM-m) recovered from a culture medium were similar to those of original PGM. 3. However, the elution profile of PGM-m on Sephacryl S-400 differed from that of PGM and closely resembled that of performic acid-treated PGM or protease-treated PGM. 4. Either of these corresponded to the so-called subunit of approximately 550,000 in mol. wt, as reported by Scawen and Allen [(1977) Biochem. J. 163, 363-368]. 5. Performic acid treatment of PGM-m led to the production of a smaller unit (unit m) having a mol. wt of about 72,000. Separate treatment of different sized components prepared from PGM-m showed the above unit m to be produced from each molecule. 6. Thus, PGM-m is a molecule partly modified by various glycosidases including endo-alpha-N-acetylgalactosaminidase and exposure of the modified part to performic acid results in oxidation. 7. Production of unit m from both larger and smaller molecules indicates the part susceptible to performic acid to exist at regular intervals on the mucus glycoprotein molecule.(ABSTRACT TRUNCATED AT 250 WORDS)