@misc{oai:repo.qst.go.jp:00072916,
 author = {中, 裕規 and 平野, 優 and 中澤, 昌美 and 阪本, 龍司 and 玉田, 太郎 and 上田, 光宏 and 平野 優 and 玉田 太郎},
 month = {Aug},
 note = {Earthworms belong to the phylum Annelida and are known to hydrolyze carbohydrates, which contributes to their ability to digest leaf litter, roots, yeast, brown algae, and fungi in soil. We previously reported that some carbohydrate hydrolases of Eisenia fetida showed the high activities in cold conditions. In addition, the endo-1,4-beta-glucanase and raw starch-digesting amylases, chitinase and beta-1,4-mannanase gene from E. fetida were cloned, expressed in Pichia pastoris (1, 2, 3, 4). The crystal structures of beta-1,4-glucanase and raw starch-digesting amylase (EF-AmyI) and beta-1,4-mannanase have been already analyzed (4, 5, 6). The negatively charged amino acids (Asp and Glu) of beta-1,4-glucanase (EF-EG2) occupied over two-thirds of accessible surface area from the total charged amino acids. It seems that the highly negatively charged surface of EF-EG2 contributes to the cold adaptation. We have applied site-directed mutagenesis (mutation of salt bridges) to improve the catalytic efficiency of beta-1,4-mannnanase at cold condition. It found that salt bridge formed by R318 played an important role for the increase of catalytic activity at low temperature condition., 14th International Chitin and Chitosan Conference},
 title = {Structural and functional analysis of carbohydrate hydrolases from Eisenia fetida},
 year = {2018}
}