@article{oai:repo.qst.go.jp:00049154,
 author = {Chatake, Toshiyuki and Yanagisawa, Yasuhide and Inoue, Rintaro and Sugiyama, Masaaki and 松尾, 龍人 and 藤原, 悟 and Ohsugi, Tadanori and Sumi, Hiroyuki and 松尾 龍人 and 藤原 悟},
 issue = {6},
 journal = {Journal of Food biochemistry},
 month = {Aug},
 note = {Vitamin K is essential for osteogenesis, and vitamin K deficiency causes osteoporosis, leading to hip fracture and coronary disease. Menaquinone-7 (MK-7), one of vitamin K subtypes, is abundantly contained in Japanese traditional fermented food natto. Bacillus subtilis natto secretes a water-soluble macromolecular complex consisting of MK-7 and peptides (natto-MK-7), although MK-7 itself is water-insoluble. However, structural properties of natto-MK-7 have not been well elucidated. In the present study, natto-MK-7 was purified from a liquid culture medium of Bacillus subtilis natto by fast protein liquid chromatography. The protein assay and electrophoresis suggest that natto-MK-7 is a complex composed of multi components including amphiphilic compounds. ‎The hydrodynamic radius of natto-MK-7 determined by the dynamic light scattering experiment suggests that natto-MK-7 has a more compact shape than that predicted in the previous size-exclusion chromatography.},
 title = {Purification and structural characterization of water-soluble menaquinone-7 produced by Bacillus subtilis natto},
 volume = {42},
 year = {2018}
}