In spite of an increasing interest in fucoidans as biologically active compounds, no convenient commercial sources with fucoidanase activity are yet available. A soil fungal strain that showed confluent growth on a minimal medium containing Miyeokgui fucoidan (MF), prepared from Korean Undaria pinnatifida sporophylls, as the sole carbon source was isolated and identified based on a 28SrDNA sequence analysis as a strain of Coniochaeta velutina, and thus tentatively named Coniochaeta velutina PF-2. A cell-free culture supernatant and intact cells of strain PF-2 were examined for the presence of fucoidanolytic activity. The increase in reducing sugars when adding the intact cell into the reaction mixture containing MF as the enzyme substrate was negligible, suggesting that the intact cell did not contain any fucoidan-degrading activities. The culture supernatant depolymerized MF (2,100 kDa) to one major medium-molecular mass fucose-containing oligosaccharides (MMFO-1), having molecular weight ~ 165.5 kDa. However, supernatant neither released the monomer L-fucose from the fucoidan nor hydrolyzed the chromogenic substrate p-nitrophenyl-α-L-fucoside, indicating that the enzyme may be an endo-acting fucoidanase rather than an α-L-fucosidase. HPAEC-PAD analysis of the TFA-hydrolyzed MMFO-1 demonstrated that the MMFO-1 consists of fucose, galactose, xylose and mannose, 504:413:4:4 respectively (mole ratios). The FT-IR spectra of MF and MMFO-1 showed no significant structural difference except for about 10% reduced level of sulfate esters in MMFO-1. This would appear to be the first report on fucoidanolytic activity by fungal strain Coniochaeta species. Moreover, this enzyme activity may be very useful for structural analyses of fucose-containing polysaccharides and the production of bioactive galactofuco-oligosaccharides.
저자
Woo Jung Kim [ Department of Biotechnology and The Research Centre for Biopharmaceutical Lead Molecule (GRRC), The Catholic University of Korea, Bucheon, Gyeonggi-do 420-743, Korea ]
Joo Woong Park [ Department of Biotechnology and The Research Centre for Biopharmaceutical Lead Molecule (GRRC), The Catholic University of Korea, Bucheon, Gyeonggi-do 420-743, Korea ]
Yong Il Park [ Department of Biotechnology and The Research Centre for Biopharmaceutical Lead Molecule (GRRC), The Catholic University of Korea, Bucheon, Gyeonggi-do 420-743, Korea ]
본 학회는 화학, 생화학, 분자생물학, 미생물학, 식품공학, 의학, 약학, 유전공학 및 생물공학, 환경 및 기타 공업 등 전 분야의 탄수화물관련 이론과 기술을 연구 발전시키고 산학협동을 통해 이를 보급하여 국내 관련 산업의 발전 및 국민생활의 과학화에 기여하고자 하며, 이러한 목표와 비젼의 실현을 위해 회원들이 적극적인 참여와 활동을 전개하고자 한다.