• Title/Summary/Keyword: Enzyme regulation

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Regulation of Glyine max Ornithine Decarboxylase by Salt and Spermine

  • Lee, Yong-Sun;Lee, Geun-Taek;Cho, Young-Dong
    • BMB Reports
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    • v.34 no.5
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    • pp.478-483
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    • 2001
  • We examined the effect of CsCl and spermine on the induction of ornithine decarboxylase (ODC), a key enzyme in polyamine synthesis form Glycine max axes. Transcription of the ODC gene was induced by 0.1 and 1 mM of CsCl, and the amount of putrescine was increased 3.5-fold by 1 mM CsCl treatment. Spermine also induced the expression of the ODC gene in a die dependent manner. However, CsCl provoked an increase in the active phosphorylated ERK (pERK), a central element of the mitogen-activated protein kinase (MAPK) cascade. Our data demonstrates an interaction between the ODC induction and the MAPK signaling pathway, and suggests that the latter may be involved in cell signaling in salt-stressed plants.

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Regulation of 3-Deoxy-D-arabinoheptulosonate-7-phosphate (DAHP) Synthase of Bacillus sp. B-6 Producing Phenazine-1-carboxylic acid

  • Kim, Kyoung-Ja
    • BMB Reports
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    • v.34 no.4
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    • pp.299-304
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    • 2001
  • The 3-Deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase is the first enzyme of aromatic amino acid-, folic acid-, and phenazine-1-carboxylic acid biosynthetic pathways. DAHP synthase of Bacillus sp. B-6 that produces phenazine-1-carboxylic acid was feedback inhibited by two intermediary metabolites of aromatic amino acid biosynthetic pathways, prephenate and chorismate, but not by other metabolites, such as anthranilic acid, shikimic acid, p-aminobenzoic acid, and 3-hydroxyanthranilic acid. DAHP synthase of Bacillus sp. B-6 was not inhibited by end products, such as aromatic amino acids, folic acid, and phenazine-1-carboxylic acid. The inhibition of DAHP synthase by prephenate and chorismate was non-competitive with respect to erythrose 4-phosphate and phosphoenolpyruvate. Prephenate and chorismate inhibited 50% of the DAHP synthase activity at concentrations of $2{\times}10^{-5}\;M$ and $1.2{\times}10^{-4}\;M$, respectively The synthesis of DAHP synthase of Bacillus sp. B-6 was not repressed by exogenous aromatic amino acids, folic acid, and phenazine 1-carboxylic acid, single or in combinations.

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A Generic Time-resolved Fluorescence Assay for Serine/threonine Kinase Activity: Application to Cdc7/Dbf4

  • Xu, Kui;Stern, Alvin S.;Levin, Wayne;Chua, Anne;Vassilev, Lyubomir T.
    • BMB Reports
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    • v.36 no.4
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    • pp.421-425
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    • 2003
  • The serine/threonine protein kinase family is a large and diverse group of enzymes that are involved in the regulation of multiple cellular pathways. Elevated kinase activity has been implicated in many diseases and frequently targeted for the development of pharmacological inhibitors. Therefore, non-radioactive antibody-based kinase assays that allow high throughput screening of compound libraries have been developed. However, they require a generation of antibodies against the phosphorylated form of a specific substrate. We report here a time-resolved fluorescence assay platform that utilizes a commercially-available generic anti-phosphothreonine antibody and permits assaying kinases that are able to phosporylate threonin residues on protein substrates. Using this approach, we developed an assay for Cdc7/Dbf4 kinase activity, determined the $K_m$ for ATP, and identified rottlerin as a non-ATP competitive inhibitor of this enzyme.

RECOMMENDED DIETARY ALLOWANCES FOR GENOMIC STABILITY

  • Fenech, Michael
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.9-9
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    • 2001
  • Several micronutrients (vitamins and minerals) are required as co-factors in DNA synthesis, DNA repair, DNA methylation and apoptosis. Some notable examples include (a) folic acid and vitamin B12 required for maintenance methylation of DNA and the synthesis of dTTP from dUTP, thus prevent the misincorporation of uracil into DNA, a highly mutagenic and chromosome-breaking event, (b) niacin, is essential in the form of the coenzymes NAD and NADP which act as a substrate for polyADPribose polymerase (PARP), an enzyme thought to facilitate efficient DNA repair and telomere length regulation and (c) zinc, apart from its antioxidant role as a co-factor in Cu/Zn SOD, it is required in its stabilizing role of the DNA-binding domain of p53 (residues 102-292) and thus is essential for apoptotic response to DNA damage. (omitted)

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Proteolytic enzyme involved in the regulation of BldD act as a transcriptional regulator in Streptomyces coelicolor A3(2)

  • Lee, Chang-Jin;Kim, Jeong-Mok;Hyung- Soon Yim;Kang, Sa-Ouk
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.49-49
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    • 2003
  • BldD is one of a set of morphological differentiation regulators in Streptomyces coelicolor. The bldD coding region was cloned and heterologously expressed in Escherichia coli. Previous analysis showed the splitting appearance of purified BldD.

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Histone Deactylase Inhibitors as Novel Target for Cancer, Diabetes, and Inflammation

  • Singh, Parul;Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.6 no.1
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    • pp.57-63
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    • 2013
  • Histone deacetylase (HDACs) is an enzyme family that deacetylates histones and non-histones protein. Availability of crystal structure of HDAC8 has been a boosting factor to generate target based inhibitors. Hydroxamic class is the most studied one to generate potent inhibitors. HDAC class I and class II enzymes are emerging as a therapeutic target for cancer, diabetes, inflammation and other diseases. DNA methylation and histone modification are epigenetic mechanism, is important for the regulation of cellular functions. HDACs enzymes play essential role in gene transcription to regulate cell proliferation, migration and death. The aim of this article is to provide a comprehensive overview about structure and function of HDACs enzymes, histone deacetylase inhibitors (HDACi) and HDACs enzymes as a therapeutic target for cancer, inflammation and diabetes.

Molecular Docking Study of Anti-diabetic Xanthones from Garcinia Xanthochymus

  • Babu, Sathya
    • Journal of Integrative Natural Science
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    • v.10 no.3
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    • pp.137-140
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    • 2017
  • Diabetes mellitus has become a major growing public health problem worldwide. More than 90% of all diabetes cases are classified as type 2 diabetes (T2D), which is also known as non-insulin dependent diabetes. Protein tyrosine phosphatase 1B (PTP1B) plays an important role in the negative regulation of insulin signal transduction pathway and has emerged as novel therapeutic strategy for the treatment of type 2 diabetes. PTP1B inhibitors enhance the sensibility of insulin receptor (IR) and have favorable curing effect for insulin resistance-related diseases. Recently twelve anti-diabetic xanthones were isolated from the bark of Garcinia xanthochymus. Hence, in the present study, molecular docking was carried out for these twelve xanthones. The objective of this work is to study the interaction of the newly isolated xanthones with PTP1B. The docking results showed that xanthones have good interactions and has better docking score with PTP1B and suggest LYS120 and ASP181 are the important residues involved in interaction between PTP1B enzyme and the xanthones.

Effects of Cofilin and PMA on $NA^+-K^+$ Pump Current in Guinea- pig Ventricular Myocytes

  • Lee, So-Young;Jaehoon Jung;Lee, Chin O.;Lee, Kyunglim
    • Proceedings of the Korean Biophysical Society Conference
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    • 2001.06a
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    • pp.45-45
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    • 2001
  • The Na$^{+}$-K$^{+}$ pump, a plasma membrane Na$^{+}$-K$^{+}$ ATPase is plays a key role in the regulation and maintenance of Na$^{+}$ and $K^{+}$ ion concentration gradients across cell membranes. This enzyme pumps three Na$^{+}$ out of and two $K^{+}$ into the cell against their electrochemical gradient by utilizing the energy derived from ATP. Therefore, the Na$^{+}$-K$^{+}$ pump generates a net outward electrical current.(omitted)ted)

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