Changes in biotin levels during production of natto, Japanese fermented soybean

The change of biotin level during production of natto (Japanese fermented soybean) was investigated in this study.  The total biotin level was measured by an agar plate bioassay using Lactobacillus plantarum ATCC 8014.  The total biotin level decreased during water soaking, but increased after the fermentation of soybeans using Bacillus subtilis var. natto (B. natto) and reached a maximum level.  The increase of total biotin was not affected by Asp, Arg, and Ile which promoted the growth of L. plantarum in high concentrations.  The peak level of biotin in the fermented soybeans was significantly higher than that of dry soybeans.  The fermented soybeans at the biotin peak level were adequate for food.  In addition, we detected 9 and 4 biotinylated polypeptides in the soybeans and B. natto used in this study, respectively.  We speculated that the increase of biotin level may depend on the increase of the 4 biotinylated polypeptides and free biotin in B. natto

青森県民の健康寿命アップ対策としての「心疾患10年リスク」の活用について(青森県の健康寿命アップと保健大学の取り組み, 第2回青森県立保健大学学術研究集会)

publisher青森市国立情報学研究所の「学術雑誌公開支援事業」により電子化されました

C-terminal Elongation of Growth-blocking Peptide Enhances Its Biological Activity and Micelle Binding Affinity*

Growth-blocking peptide (GBP) is a hormone-like peptide that suppresses the growth of the host armyworm. Although the 23-amino acid GBP (1–23 GBP) is expressed in nonparasitized armyworm plasma, the parasitization by wasp produces the 28-amino acid GBP (1–28 GBP) through an elongation of the C-terminal amino acid sequence. In this study, we characterized the GBP variants, which consist of various lengths of the C-terminal region, by comparing their biological activities and three-dimensional structures. The results of an injection study indicate that 1–28 GBP most strongly suppresses larval growth. NMR analysis shows that these peptides have basically the same tertiary structures and that the extension of the C-terminal region is disordered. However, the C-terminal region of 1–28 GBP undergoes a conformational transition from a random coiled state to an α-helical state in the presence of dodecylphosphocholine micelles. This suggests that binding of the C-terminal region would affect larval growth activity