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991.
In order to identify the number and types of peptide chains in thyroglobulin, noniodinated 19-S thyroglobulin obtained from goitrogen-treated hogs was exhaustively digested with trypsin (EC 3.4.4.4) after reduction and S-carboxymethylation. The digestion mixture was preliminarily separated into 30 fractions on Sephadex G-100 or G-15 and SE-Sephadex columns. The number of various tryptic peptides contained in each fraction was determined on peptide maps, where spots were detected with ninhydrin for total peptides and with each specific reagent for arginine, histidine or tyrosine-containing peptides. The number of total peptides observed in most of the fractions was estimated to be half the number of lysine plus arginine residues found in each fraction per mole of thyroglobulin, and the number of specific peptides was also close to half the number of each specific amino acid. These findings imply that thyroglobulin has 2-fold symmetry in the structure at the level of tryptic fragments and thus probably at the level of intact peptide chains. 相似文献
992.
H Hayashi J R Knowles J R Katze J Lapointe D S?ll 《The Journal of biological chemistry》1970,245(6):1401-1406
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Phi-X-174 coat protein mutants affecting DNA synthesis 总被引:3,自引:0,他引:3
J E Siegel M N Hayashi M Hayashi 《Biochemical and biophysical research communications》1968,31(5):774-778
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Taichi Ikedo Manabu Minami Hiroharu Kataoka Kosuke Hayashi Manabu Nagata Risako Fujikawa Fumiyoshi Yamazaki Mitsutoshi Setou Masayuki Yokode Susumu Miyamoto 《Biochemical and biophysical research communications》2018,495(1):332-338
Object
The wall thickness of intracranial aneurysms (IAs) is heterogeneous. Although thinning of the IA wall is thought to contribute to IA rupture, the underlying mechanism remains poorly understood. Recently, imaging mass spectroscopy (IMS) has been used to reveal the distribution of phospholipids in vascular diseases. To investigate the feature of phospholipid composition of IA walls, we conducted IMS in a rat model of experimentally induced IA.Material and methods
IAs were surgically induced in 7-week-old male rats and analyzed by IMS in negative-ion mode.Results
A molecule at m/z 885.5 was more abundant in the thickened wall than in the thinned wall (P = 0.03). Multiple-stage mass spectroscopy revealed the molecule to be phosphatidylinositol containing stearic acid and arachidonic acid (PI 18:0/20:4). Immunohistochemistry indicated that vascular smooth muscle cells (SMCs) in the thickened wall had dedifferentiated phenotypes. To investigate the relationship between accumulation of PI (18:0/20:4) and phenotypic changes in SMCs, we subjected primary mouse aortic SMCs to liquid chromatography–tandem mass spectrometry. Notably, dedifferentiated SMCs had 1.3-fold more PI (18:0/20:4) than partly differentiated SMCs.Conclusions
Our study demonstrated the heterogeneity in phospholipid composition of the aneurysmal walls using experimentally induced IAs. PI (18:0/20:4) accumulated at high levels in the thickened aneurysmal wall where synthetic dedifferentiated SMCs exist, suggesting that this phospholipid may be involved in the phenotypic switching of medial SMCs in the IA wall. 相似文献999.
Keiko Hayashi Yoshikatsu Fujita Taketo Ashizawa Fumihiko Suzuki Yoshiaki Nagamura Yuriko Hayano‐Saito 《The Plant journal : for cell and molecular biology》2016,85(1):46-56
The hypersensitive response (HR) of plants is one of the earliest responses to prevent pathogen invasion. A brown dot lesion on a leaf is visual evidence of the HR against the blast fungus Magnaporthe oryzae in rice, but tracking the browning process has been difficult. In this study, we induced the HR in rice cultivars harboring the blast resistance gene Pit by inoculation of an incompatible M. oryzae strain, which generated a unique resistance lesion with a brown ring (halo) around the brown fungal penetration site. Inoculation analysis using a plant harboring Pit but lacking an enzyme that catalyzes tryptamine to serotonin showed that high accumulation of the oxidized form of serotonin was the cause of the browning at the halo and penetration site. Our analysis of the halo browning process in the rice leaf revealed that abscisic acid enhanced biosynthesis of serotonin under light conditions, and serotonin changed to the oxidized form via hydrogen peroxide produced by light. The dramatic increase in serotonin, which has a high antioxidant activity, suppressed leaf damage outside the halo, blocked expansion of the browning area and attenuated inhibition of plant growth. These results suggest that serotonin helps to reduce biotic stress in the plant by acting as a scavenger of oxygen radicals to protect uninfected tissues from oxidative damage caused by the HR. The deposition of its oxide at the HR lesion is observed as lesion browning. 相似文献
1000.
Megumi Narukawa‐Nara Ayako Nakamura Ko Kikuzato Yusuke Kakei Akiko Sato Yuka Mitani Yumiko Yamasaki‐Kokudo Takahiro Ishii Ken‐ichiro Hayashi Tadao Asami Takehiko Ogura Shigeo Yoshida Shozo Fujioka Takashi Kamakura Tsutomu Kawatsu Masanori Tachikawa Kazuo Soeno Yukihisa Shimada 《The Plant journal : for cell and molecular biology》2016,87(3):245-257
We previously reported l ‐α‐aminooxy‐phenylpropionic acid (AOPP) to be an inhibitor of auxin biosynthesis, but its precise molecular target was not identified. In this study we found that AOPP targets TRYPTOPHAN AMINOTRANSFERASE of ARABIDOPSIS 1 (TAA1). We then synthesized 14 novel compounds derived from AOPP to study the structure–activity relationships of TAA1 inhibitors in vitro. The aminooxy and carboxy groups of the compounds were essential for inhibition of TAA1 in vitro. Docking simulation analysis revealed that the inhibitory activity of the compounds was correlated with their binding energy with TAA1. These active compounds reduced the endogenous indole‐3‐acetic acid (IAA) content upon application to Arabidopsis seedlings. Among the compounds, we selected 2‐(aminooxy)‐3‐(naphthalen‐2‐yl)propanoic acid (KOK1169/AONP) and analyzed its activities in vitro and in vivo. Arabidopsis seedlings treated with KOK1169 showed typical auxin‐deficient phenotypes, which were reversed by exogenous IAA. In vitro and in vivo experiments indicated that KOK1169 is more specific for TAA1 than other enzymes, such as phenylalanine ammonia‐lyase. We further tested 41 novel compounds with aminooxy and carboxy groups to which we added protection groups to increase their calculated hydrophobicity. Most of these compounds decreased the endogenous auxin level to a greater degree than the original compounds, and resulted in a maximum reduction of about 90% in the endogenous IAA level in Arabidopsis seedlings. We conclude that the newly developed compounds constitute a class of inhibitors of TAA1. We designated them ‘pyruvamine’. 相似文献