Journal of Biological Macromolecules
Online ISSN : 2187-3240
Print ISSN : 1347-2194
ISSN-L : 1347-2194
21 巻, 2 号
選択された号の論文の4件中1~4を表示しています
  • Magnesium and Mg2+ Transport Proteins in Cells
    Sumio Ishijima
    2021 年 21 巻 2 号 p. 55-67
    発行日: 2021年
    公開日: 2021/12/14
    ジャーナル フリー
    Magnesium is one of the most important and abundant divalent cations in living cells. Organisms must maintain physiological levels of Mg2+ because this divalent cation is critical for the stabilization of membranes and ribosomes and for the neutralization of nucleic acids. Over 300 enzymes are known to be Mg-dependent. The cellular concentration of Mg2+ is regulated by transmembrane pathways. Prokaryotes carry three classes of Mg2+ transport systems: CorA, MgtE, and MgtA. Some of eukaryotic Mg2+ transport proteins have some similarity to those found in prokaryotes. Mitochondrial RNA splicing protein 2 (MRS2) shares many of properties of the bacterial CorA protein. The Solute Carrier Family 41 Member 1 (SLC41A1) and Cyclin and CBS Domain Divalent Metal Cation Transport Mediator (CNNM) family proteins have a similarity with some regions of the bacterial MgtE and CorC proteins, respectively. Mammalian Mg2+ homeostasis is also regulated by Mg2+ transport proteins including Transient Receptor Potential Cation Channel Subfamily M, Member 6/7 (TRPM6/7), Claudin-16, Magnesium Transporter 1 (MAGT1), and Nonimprinted in Prader-Willi/Angelman Syndrome Region (NIPA) proteins that are not represented in prokaryotic genomes. These eukaryotic Mg2+ transport proteins have no obvious amino acid sequence similarities, indicating that there are many ways to transport Mg2+ across membranes.
  • Structural analysis of the HDC Y334F mutant
    Hirofumi Komori, Yoko Nitta
    2021 年 21 巻 2 号 p. 69-74
    発行日: 2021年
    公開日: 2021/12/14
    ジャーナル フリー
    Histamine is an important chemical messenger involved in a wide variety of physiological reactions. L-histidine decarboxylase (HDC) is the primary enzyme responsible for the synthesis of histamine from histidine in a one-step reaction. So far, the crystal structure of human HDC complex with the inhibitor has been determined, and the tyrosine residue (Y334) in the catalytic loop is suggested to play an important role in the decarboxylation reaction. In this study, Y334F, a point mutant of human HDC was subjected to X-ray crystallographic analysis under the same crystallization conditions that were used for the HDC–inhibitor complex; however, despite maintaining the same conditions, different types of crystals of the Y334F mutant were obtained. Furthermore, the structure of the reaction intermediate was determined by soaking the substrate histidine into the crystal of Y334F mutant. In this study, we discuss the role of the catalytic loop in histidine decarboxylation based on the structure of the reaction intermediate.
  • The effect of ingestion of an ethyl α-D-glucoside on human skin
    Masaki Mitsui, Koji Tokuda, Masayuki Machida, Kenji Ozeki
    2021 年 21 巻 2 号 p. 75-87
    発行日: 2021年
    公開日: 2021/12/14
    ジャーナル フリー
    Measurements were taken at 30 places on the inner side of both upper arms each week as part of various drinking tests, using a device that quantifies the measurements as the collagen score. In the first experiment, an immediate increase in the collagen score by 8 points in the first week and a continuous increase of 20 points in the fourth week were observed. In the second experiment, immediate and continuous effects were observed, with increase of 6 and 10 points in the collagen score in the first and fourth weeks, respectively. The third experiment showed that the collagen score in the first and second weeks increased by 4 and 9 points, respectively, and the keratinous moisture content increased by 3 and 8 points, respectively. These findings indicate that ethyl α-D-glucoside intake improves both the resilience and glow of the skin.
  • Apolipoprotein assay for assessing lipoprotein in hepatocyte
    Sayaka Tomatsu, Masaki Takahashi, Gen Toshima, Shiho Nakagawa, Junichi ...
    2021 年 21 巻 2 号 p. 89-92
    発行日: 2021年
    公開日: 2021/12/14
    ジャーナル フリー
    We previously assessed anti-lipidemic activity by evaluating lipoprotein profiles in PXB-cells®, human primary hepatocytes from humanized mice livers, using LipoSEARCH®. This highly sensitive assay system detects low levels of extracellular lipoproteins; however, an increased throughput is needed to simultaneously assay multiple analytes. We herein investigated whether an enzyme-linked immunosolvent assay (ELISA) on apolipoproteins (APO) accurately detects reductions in extracellular lipoprotein levels in PXB-cells treated with fenofibrate as an alternative to LipoSEARCH. These results suggest the applicability of ELISA on APO to the conventional screening of anti-lipidemic activities in a large number of candidates.
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