G-Quadruplexes: Higher-order DNA and RNA structures formed from guanine-rich sequences. They are formed around a core of at least 2 stacked tetrads of hydrogen-bonded GUANINE bases. They can be formed from one two or four separate strands of DNA (or RNA) and can display a wide variety of topologies, which are a consequence of various combinations of strand direction, length, and sequence. (From Nucleic Acids Res. 2006;34(19):5402-15)Nanotechnology: The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.Nanostructures: Materials which have structured components with at least one dimension in the range of 1 to 100 nanometers. These include NANOCOMPOSITES; NANOPARTICLES; NANOTUBES; and NANOWIRES.Diagnostic Equipment: Nonexpendable items used in examination.Gold Radioisotopes: Unstable isotopes of gold that decay or disintegrate emitting radiation. Au 185-196, 198-201, and 203 are radioactive gold isotopes.Dendrimers: Tree-like, highly branched, polymeric compounds. They grow three-dimensionally by the addition of shells of branched molecules to a central core. The overall globular shape and presence of cavities gives potential as drug carriers and CONTRAST AGENTS.Nanowires: Nanometer-scale wires made of materials that conduct electricity. They can be coated with molecules such as antibodies that will bind to proteins and other substances.DNA, Single-Stranded: A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Fluorescent Dyes: Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.Glioma: Benign and malignant central nervous system neoplasms derived from glial cells (i.e., astrocytes, oligodendrocytes, and ependymocytes). Astrocytes may give rise to astrocytomas (ASTROCYTOMA) or glioblastoma multiforme (see GLIOBLASTOMA). Oligodendrocytes give rise to oligodendrogliomas (OLIGODENDROGLIOMA) and ependymocytes may undergo transformation to become EPENDYMOMA; CHOROID PLEXUS NEOPLASMS; or colloid cysts of the third ventricle. (From Escourolle et al., Manual of Basic Neuropathology, 2nd ed, p21)Brain Neoplasms: Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.Glioblastoma: A malignant form of astrocytoma histologically characterized by pleomorphism of cells, nuclear atypia, microhemorrhage, and necrosis. They may arise in any region of the central nervous system, with a predilection for the cerebral hemispheres, basal ganglia, and commissural pathways. Clinical presentation most frequently occurs in the fifth or sixth decade of life with focal neurologic signs or seizures.Anticonvulsants: Drugs used to prevent SEIZURES or reduce their severity.Astrocytoma: Neoplasms of the brain and spinal cord derived from glial cells which vary from histologically benign forms to highly anaplastic and malignant tumors. Fibrillary astrocytomas are the most common type and may be classified in order of increasing malignancy (grades I through IV). In the first two decades of life, astrocytomas tend to originate in the cerebellar hemispheres; in adults, they most frequently arise in the cerebrum and frequently undergo malignant transformation. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2013-7; Holland et al., Cancer Medicine, 3d ed, p1082)Neoplasm Invasiveness: Ability of neoplasms to infiltrate and actively destroy surrounding tissue.Neoplasm Recurrence, Local: The local recurrence of a neoplasm following treatment. It arises from microscopic cells of the original neoplasm that have escaped therapeutic intervention and later become clinically visible at the original site.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Cell Line, Tumor: A cell line derived from cultured tumor cells.Antineoplastic Agents: Substances that inhibit or prevent the proliferation of NEOPLASMS.Grewia: A plant genus of the family TILIACEAE. Members contain lupeol and betulin TRITERPENES.2-Aminopurine: A purine that is an isomer of ADENINE (6-aminopurine).Herpes Simplex: A group of acute infections caused by herpes simplex virus type 1 or type 2 that is characterized by the development of one or more small fluid-filled vesicles with a raised erythematous base on the skin or mucous membrane. It occurs as a primary infection or recurs due to a reactivation of a latent infection. (Dorland, 27th ed.)Fluorenes: A family of diphenylenemethane derivatives.Acyclovir: A GUANOSINE analog that acts as an antimetabolite. Viruses are especially susceptible. Used especially against herpes.Herpes Genitalis: Infection of the genitals (GENITALIA) with HERPES SIMPLEX VIRUS in either the males or the females.Medicare Part B: The voluntary portion of Medicare, known as the Supplementary Medical Insurance (SMI) Program, that includes physician's services, home health care, medical services, outpatient hospital services, and laboratory, pathology, and radiology services. All persons entitled to Medicare Part A may enroll in Medicare Part B on a monthly premium basis.Simplexvirus: A genus of the family HERPESVIRIDAE, subfamily ALPHAHERPESVIRINAE, consisting of herpes simplex-like viruses. The type species is HERPESVIRUS 1, HUMAN.Keratitis, Dendritic: A form of herpetic keratitis characterized by the formation of small vesicles which break down and coalesce to form recurring dendritic ulcers, characteristically irregular, linear, branching, and ending in knoblike extremities. (Dictionary of Visual Science, 3d ed)Antiviral Agents: Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.Graphite: An allotropic form of carbon that is used in pencils, as a lubricant, and in matches and explosives. It is obtained by mining and its dust can cause lung irritation.Oxides: Binary compounds of oxygen containing the anion O(2-). The anion combines with metals to form alkaline oxides and non-metals to form acidic oxides.Nanomedicine: The branch of medicine concerned with the application of NANOTECHNOLOGY to the prevention and treatment of disease. It involves the monitoring, repair, construction, and control of human biological systems at the molecular level, using engineered nanodevices and NANOSTRUCTURES. (From Freitas Jr., Nanomedicine, vol 1, 1999).Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Nanoparticles: Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.Nanotubes, Carbon: Nanometer-sized tubes composed mainly of CARBON. Such nanotubes are used as probes for high-resolution structural and chemical imaging of biomolecules with ATOMIC FORCE MICROSCOPY.Conductometry: Determination of the quantity of a material present in a mixture by measurement of its effect on the electrical conductivity of the mixture. (Webster, 3d ed)Green Chemistry Technology: Pollution prevention through the design of effective chemical products that have low or no toxicity and use of chemical processes that reduce or eliminate the use and generation of hazardous substances.
(1/327) Marker effects on reversion of T4rII mutants.

The frequencies of 2-aminopurine- and 5-bromouracil-induced A:T leads to G:C transitions were compared at nonsense sites throughout the rII region of bacteriophage T4. These frequencies are influenced both by adjacent base pairs within the nonsense codons and by extracodonic factors. Following 2AP treatment, they are high in amber (UAG) and lower in opal (UGA) codons than in allelic ochre (UAA) codons. In general, 5BU-induced transitions are more frequent in both amber and opal codons than in the allelic ochre codons. 2AP- and 5BU-induced transition frequencies in the first and third positions of opal codons are correlated with those in the corresponding positions of the allelic ochre codons. Similarly, the frequencies of 2AP-induced transition in the first and second positions of amber codons and their ochre alleles are correlated. However, there is little correlation between the frequencies of 5BU-induced transitions in the first and second positions of allelic amber and ochre codons.  (+info)

(2/327) Base pairing of anhydrohexitol nucleosides with 2,6-diaminopurine, 5-methylcytosine and uracil asbase moiety.

Hexitol nucleic acids (HNAs) with modified bases (5-methylcytosine, 2,6-diaminopurine or uracil) were synthesized. The introduction of the 5-methylcytosine base demonstrates that N -benzoylated 5-methylcytosyl-hexitol occurs as the imino tautomer. The base pairing systems (G:CMe, U:D, T:D and U:A) obey Watson-Crick rules. Substituting hT for hU, hCMefor hC and hD for hA generally leads to increased duplex stability. In a single case, replacement of hC by hCMedid not result in duplex stabilization. This sequence-specific effect could be explained by the geometry of the model duplex used for carrying out the thermal stability study. Generally, polypurine HNA sequences give more stable duplexes with their RNA complement than polypyrimidine HNA sequences. This observation supports the hypothesis that, besides changes in stacking pattern, the difference in conformational stress between purine and pyrimidine nucleosides may contribute to duplex stability. Introduction of hCMeand hD in HNA sequences further increases the potential of HNA to function as a steric blocking agent.  (+info)

(3/327) Direct selection for mutators in Escherichia coli.

We have constructed strains that allow a direct selection for mutators of Escherichia coli on a single plate medium. The plate selection is based on using two different markers whose reversion is enhanced by a given mutator. Plates containing limiting amounts of each respective nutrient allow the growth of ghost colonies or microcolonies that give rise to full-size colonies only if a reversion event occurs. Because two successive mutational events are required, mutator cells are favored to generate full-size colonies. Reversion of a third marker allows direct visualization of the mutator phenotype by the large number of blue papillae in the full-size colonies. We also describe plate selections involving three successive nutrient markers followed by a fourth papillation step. Different frameshift or base substitution mutations are used to select for mismatch-repair-defective strains (mutHLS and uvrD). We can detect and monitor mutator cells arising spontaneously, at frequencies lower than 10(-5) in the population. Also, we can measure a mutator cascade, in which one type of mutator (mutT) generates a second mutator (mutHLS) that then allows stepwise frameshift mutations. We discuss the relevance of mutators arising on a single medium as a result of cells overcoming successive growth barriers to the development and progression of cancerous tumors, some of which are mutator cell lines.  (+info)

(4/327) Purine analogue 6-methylmercaptopurine riboside inhibits early and late phases of the angiogenesis process.

Angiogenesis has been identified as an important target for antineoplastic therapy. The use of purine analogue antimetabolites in combination chemotherapy of solid tumors has been proposed. To assess the possibility that selected purine analogues may affect tumor neovascularization, 6-methylmercaptopurine riboside (6-MMPR), 6-methylmercaptopurine, 2-aminopurine, and adenosine were evaluated for the capacity to inhibit angiogenesis in vitro and in vivo. 6-MMPR inhibited fibroblast growth factor-2 (FGF2)-induced proliferation and delayed the repair of mechanically wounded monolayer in endothelial GM 7373 cell cultures. 6-MMPR also inhibited the formation of solid sprouts within fibrin gel by FGF2-treated murine brain microvascular endothelial cells and the formation of capillary-like structures on Matrigel by murine aortic endothelial cells transfected with FGF2 cDNA. 6-MMPR affected FGF2-induced intracellular signaling in murine aortic endothelial cells by inhibiting the phosphorylation of extracellular signal-regulated kinase-2. The other molecules were ineffective in all of the assays. In vivo, 6-MMPR inhibited vascularization in the chick embryo chorioallantoic membrane and prevented blood vessel formation induced by human endometrial adenocarcinoma specimens grafted onto the chorioallantoic membrane. Also, topical administration of 6-MMPR caused the regression of newly formed blood vessels in the rabbit cornea. Thus, 6-MMPR specifically inhibits both the early and the late phases of the angiogenesis process in vitro and exerts a potent anti-angiogenic activity in vivo. These results provide a new rationale for the use of selected purine analogues in combination therapy of solid cancer.  (+info)

(5/327) The comparative effects of famciclovir and valacyclovir on herpes simplex virus type 1 infection, latency, and reactivation in mice.

Infections by herpes simplex virus (HSV) cannot yet be eliminated, but the severity of the disease can be reduced. Two newer drugs with established efficacy for such infections, famciclovir and valacyclovir, were tested in a mouse eye model of HSV infection. Both drugs significantly reduced mortality and titers of virus shed from the eyes of mice infected with an otherwise lethal dose of HSV type 1 (HSV-1). Similar titers of HSV-1 were found in the eyes, ganglia, and brains of treated animals. Although valacyclovir reduced the latent viral DNA load better in these studies than did famciclovir, rates of reactivation by explantation and UV exposure were the same. Thus, in this study, famciclovir and valacyclovir were equally effective in limiting the virulence and spread of HSV-1, despite their biochemical and pharmacologic differences.  (+info)

(6/327) Characterization of the interaction of lambda exonuclease with the ends of DNA.

Lambda exonuclease processively degrades one strand of double-stranded DNA (dsDNA) in the 5"-3" direction. To understand the mechanism through which this enzyme generates high processivity we are analyzing the first step in the reaction, namely the interaction of lambda exonuclease with the ends of substrate DNA. Endonuclease mapping of lambda exonuclease bound to DNA has shown that the enzyme protects approximately 13-14 bp on dsDNA, and no nucleo-tides on the single-stranded tail of the DNA product. We have developed a rapid fluorescence-based assay using 2-aminopurine and measured the steady-state rate constants for different end-structures of DNA. The relative k(cat)for 5" ends decreases in the order 5" recessed > blunt >> 5" overhang. However, k(cat)/K(m)remains relatively constant for these different structures suggesting they are all used equally efficiently as substrates. From these data we propose that a single-stranded 5" overhang end can bind non-productively to the enzyme and the non-hydrolyzed strand is required to aid in the proper alignment of the 5" end. We have also measured the length-dependence of the steady-state rate para-meters and find that they are consistent with a high degree of processivity.  (+info)

(7/327) Mechanism of action and in vitro activity of 1',3'-dioxolanylpurine nucleoside analogues against sensitive and drug-resistant human immunodeficiency virus type 1 variants.

(-)-Beta-D-1',3'-Dioxolane guanosine (DXG) and 2,6-diaminopurine (DAPD) dioxolanyl nucleoside analogues have been reported to be potent inhibitors of human immunodeficiency virus type 1 (HIV-1). We have recently conducted experiments to more fully characterize their in vitro anti-HIV-1 profiles. Antiviral assays performed in cell culture systems determined that DXG had 50% effective concentrations of 0.046 and 0.085 microM when evaluated against HIV-1(IIIB) in cord blood mononuclear cells and MT-2 cells, respectively. These values indicate that DXG is approximately equipotent to 2', 3'-dideoxy-3'-thiacytidine (3TC) but 5- to 10-fold less potent than 3'-azido-2',3'-dideoxythymidine (AZT) in the two cell systems tested. At the same time, DAPD was approximately 5- to 20-fold less active than DXG in the anti-HIV-1 assays. When recombinant or clinical variants of HIV-1 were used to assess the efficacy of the purine nucleoside analogues against drug-resistant HIV-1, it was observed that AZT-resistant virus remained sensitive to DXG and DAPD. Virus harboring a mutation(s) which conferred decreased sensitivity to 3TC, 2',3'-dideoxyinosine, and 2',3'-dideoxycytidine, such as a 65R, 74V, or 184V mutation in the viral reverse transcriptase (RT), exhibited a two- to fivefold-decreased susceptibility to DXG or DAPD. When nonnucleoside RT inhibitor-resistant and protease inhibitor-resistant viruses were tested, no change in virus sensitivity to DXG or DAPD was observed. In vitro drug combination assays indicated that DXG had synergistic antiviral effects when used in combination with AZT, 3TC, or nevirapine. In cellular toxicity analyses, DXG and DAPD had 50% cytotoxic concentrations of greater than 500 microM when tested in peripheral blood mononuclear cells and a variety of human tumor and normal cell lines. The triphosphate form of DXG competed with the natural nucleotide substrates and acted as a chain terminator of the nascent DNA. These data suggest that DXG triphosphate may be the active intracellular metabolite, consistent with the mechanism by which other nucleoside analogues inhibit HIV-1 replication. Our results suggest that the use of DXG and DAPD as therapeutic agents for HIV-1 infection should be explored.  (+info)

(8/327) In vitro induction of human immunodeficiency virus type 1 variants resistant to phosphoralaninate prodrugs of Z-methylenecyclopropane nucleoside analogues.

Two methylenecyclopropane nucleoside analogues with a phenylphosphoralaninate moiety, QYL-685 and QYL-609, exert potent and specific activities against human immunodeficiency virus type 1 strain LAI (HIV-1(LAI)) and HIV-2 in vitro. In this study, we induced HIV-1 variants resistant to QYL-685 by exposing HIV-1(LAI) to increasing concentrations of QYL-685. After 16 passages, the virus (HIV-1(P16)) was less sensitive to QYL-685 (104-fold), QYL-609 (>41-fold), and (-)-beta-2',3'-dideoxy-3'-thiacytidine (3TC) (>1, 100-fold) than was HIV-1(LAI) and contained an M184I mutation. Two infectious clones, HIV-1(M184I) and HIV-1(M184V), were resistant to QYL-685, QYL-609, and 3TC, confirming that the M184I mutation was responsible for the observed resistance. Viral-fitness analyses (competitive HIV-1 replication assays) revealed that in the absence of drugs, M184I and M184V conferred a replication disadvantage on the virus compared to the replication efficiency of the wild-type infectious clone (HIV-1(wt)). However, in the presence of QYL-685 (4 microM), HIV-1(M184I) and HIV-1(M184V) showed greater fitness than HIV-1(wt). These data may provide structural and virological relevance with regard to the emergence of M184I and M184V substitutions in HIV-1.  (+info)

*  2-Aminopurine
... , a purine analog of guanine and adenine, is a fluorescent molecular marker used in nucleic acid research. It most ... Nucleic acid analogues Jean JM, Hall KB (2001). "2-Aminopurine fluorescence quenching and lifetimes: role of base stacking". ... observation of a protonated base pair between 2-aminopurine and cytosine in an oligonucleotide by proton NMR". Proc. Natl. Acad ...
*  Site-directed mutagenesis
... examples of such chemicals are aminopurine, nitrosoguanidine, and bisulfite. Site-directed mutagenesis was achieved in 1974 in ... 82 (2): 488-92. doi:10.1073/pnas.82.2.488. PMC 397064 . PMID 3881765. Wells, J. A.; Estell, D. A. (1988). "Subtilisin--an ... 124 (2): 343-358. doi:10.1016/0022-2836(78)90303-0. PMID 712841. Hutchison Ca, 3.; Edgell, M. H. (1971). "Genetic Assay for ... 2 (9): 1096-1103. PMC 369902 . PMID 6983647. McHugh, G. L.; Miller, C. G. (1974). "Isolation and Characterization of Proline ...
*  Mutagenesis (molecular biology technique)
Such chemicals include aminopurine, which induces AT to GC transition, while nitrosoguanidine, bisulfite, and N4- ... 400 (1-2): 25-32. doi:10.1016/s0027-5107(98)00061-x. PMID 9685575. Flibotte S, Edgley ML, Chaudhry I, Taylor J, Neil SE, Rogula ... 124 (2): 343-358. doi:10.1016/0022-2836(78)90303-0. PMID 712841. Papworth, C., Bauer, J. C., Braman, J. and Wright, D. A. (1996 ... 2 (9): 1096-1103. PMC 369902 . PMID 6983647. McHugh, G. L.; Miller, C. G. (1974). "Isolation and Characterization of Proline ...
*  DNA base flipping
2-Aminopurine is a base that is structurally similar to adenine, but is very fluorescent when flipped out from the DNA duplex. ... 74 (2): 299-307. doi:10.1016/0092-8674(93)90421-l. PMID 8343957. Brunger A.T. (1992)"X-PLOR, Version 3.1 : A system for x-ray ... Other fluorescent probes used to study DNA base flipping are 6MAP (4‑amino‑6‑methyl‑7(8H)‑pteridone) and Pyrrolo‑C (3-[β-D-2- ... 31 (2): 89-97. doi:10.1016/j.tibs.2005.12.008. ISSN 0968-0004. PMID 16403636. Nakao, M (2001). "Epigenetics: Interaction of DNA ...
*  Balaji Prakash
"Investigating the inhibitory potential of 2-Aminopurine metal complexes against serine/threonine protein kinases from ...
*  Frameshift mutation
85 (2): 142-154. doi:10.1016/j.ajhg.2009.06.022. PMC 2725244 . PMID 19679224. Walsh, T.; Casadei, S.; Lee, M. K.; Pennil, C. C ... 153 (2): S4-S14. doi:10.1016/j.jpeds.2008.05.005. PMC 2810958 . PMID 18639722. Iannuzzi, MC; Stern, RC; Collins, FS; Hon, CT; ... 13 (2): R9. doi:10.1186/gb-2012-13-2-r9. PMC 3334572 . PMID 22322200. Tucker, Tracy; Marra, Marco; Friedman, Jan M. (2009). " ... Retrieved 2 June 2009. Frameshift Mutation at the US National Library of Medicine Medical Subject Headings (MeSH) NCBI dbSNP ...
*  Excimer
46(2):193-209. Link Conibear PB, Bagshaw CR, Fajer PG, Kovacs M, Malnasi-Csizmadia A. (2003). Myosin cleft movement and its ... Stereospecific 1,2 and 1,4 cycloadditions Kenneth E. Wilzbach and Louis Kaplan J. Am. Chem. Soc.; 1971; 93(8) pp 2073 - 2074; ... 2007, 46, 663 - 665 doi:10.1002/anie.200603337 1-cyanobicyclo[4.2.0]octa-2,4-dienes and their synthesis United States Patent ... 2+4]cycloaddition to the para product (C) with simple alkenes such as the isomers of 2-butene. In these reactions it is the ...
*  Carbocyclic nucleoside
7 (2): 127-132. doi:10.1016/S0960-894X(96)00594-X. Borthwick AD, Butt S, Biggadike K, Exall AM, Roberts SM, Youds PM, Kirk BE, ... 2. JAI Press Inc. pp. 89-146. ISBN 1-55938-693-2. Cameron JM (December 1993). "New antiherpes drugs in development". Reviews in ... 156 (2): 1046-1053. doi:10.1016/S0006-291X(88)80950-1. PMID 2847711. CS1 maint: Uses authors parameter (link) Carter SG, ... Carbocyclic (E)-5-(2-bromovinyl)-2-deoxyuridine( (+) C-BVDU) GR95168 possesses activity against herpes simplex virus type l ( ...
*  5-Bromouracil
It is used mainly as an experimental mutagen, but its deoxyriboside derivative (5-bromo-2-deoxy-uridine) is used to treat ... 5-Bromouracil, systematic name 5-bromopyrimidine-2,4-dione, (abbreviated as 5-BrU, 5BrUra or br5Ura) is a brominated derivative ... and can induce DNA mutation in the same way as 2-aminopurine. ...
*  Nucleic acid analogue
Another example of a metal complexing to natural nucleobases is the formation of A-Zn-T and G-Zn-C at high pH; Co+2 and Ni+2 ... 2-aminoadenine is an adenine substituting for a base in S-2L cyanophage DNA. Nature. 1977 Nov 24;270(5635):369-70. Johnson SC ... 37 (2): e14. doi:10.1093/nar/gkn956. Yamashige, R.; et al. (2012). "Highly specific unnatural base pair systems as a third base ... 1,3-Diaza-2-oxophenothiazine, tC, has a fluorescence quantum yield of approximately 0.2 both in single- and in double-strands ...
*  List of MeSH codes (D03)
2,3,4,5-tetrahydro-8-chloro-3-methyl-5-phenyl-1h-3-benzazepin-7-ol MeSH D03.438.079.800 --- 2,3,4,5-tetrahydro-7,8-dihydroxy-1- ... quinolizin-2-ol, 2-ethyl-1,3,4,6,7,11b-hexahydro-3-isobutyl-9,10-dimethoxy- MeSH D03.438.834.775 --- sparteine MeSH D03.438. ... 5-nitro-2-furyl)vinyl)-1,2,4-oxadiazole MeSH D03.383.312.649.290 --- fanft MeSH D03.383.312.649.308 --- furagin MeSH D03.383. ... 5-nitro-2-furyl)vinyl)-1,2,4-oxadiazole MeSH D03.383.129.462.580.400 --- 4-chloro-7-nitrobenzofurazan MeSH D03.383.129.462. ...
*  Biomolecular engineering
... days of research in this field yielded discoveries about the potential of certain chemicals such as bisulfite and aminopurine ... 16 (2): 159-168. doi:10.1002/bit.260160202. Zhang Ya-Tao, Zhi, Tian-Tian, Zhang, Lin, Huang, He, Chen, Huan-Lin. (2009). " ... 16 (1): 2-16. doi:10.1021/bp088059d. Slabaugh, Michael R. & Seager, Spencer L. (2007). Organic and Biochemistry for Today (6th ... These monosaccharides consist of a five to six carbon ring that contains carbon, hydrogen, and oxygen - typically in a 1:2:1 ...
2-Aminopurine - Wikipedia  2-Aminopurine - Wikipedia
2-Aminopurine, a purine analog of guanine and adenine, is a fluorescent molecular marker used in nucleic acid research. It most ... Nucleic acid analogues Jean JM, Hall KB (2001). "2-Aminopurine fluorescence quenching and lifetimes: role of base stacking". ... observation of a protonated base pair between 2-aminopurine and cytosine in an oligonucleotide by proton NMR". Proc. Natl. Acad ...
more infohttps://en.wikipedia.org/wiki/2-Aminopurine
DNA nanodevices monitored with fluorogenic looped-out 2-aminopurine - Analyst (RSC Publishing)  DNA nanodevices monitored with fluorogenic looped-out 2-aminopurine - Analyst (RSC Publishing)
It is found that looped-out 2-AP, an analogue of adenine, in split parallel G-quadruplexes, triplexes and duplexes always shows ... We report several DNA nanodevices monitored with fluorogenic looped-out 2-aminopurine. ... DNA nanodevices monitored with fluorogenic looped-out 2-aminopurine P. Peng, Y. Du and T. Li, Analyst, 2018, Advance Article , ... It is found that looped-out 2-AP, an analogue of adenine, in split parallel G-quadruplexes, triplexes and duplexes always shows ...
more infohttp://pubs.rsc.org/en/content/articlelanding/2018/an/c7an01953j
Inhibition of Endoplasmic Reticulum Stress and Atherosclerosis by 2-Aminopurine in Apolipoprotein E-Deficient Mice  Inhibition of Endoplasmic Reticulum Stress and Atherosclerosis by 2-Aminopurine in Apolipoprotein E-Deficient Mice
Lichun Zhou,1 Dezhi Yang,2 Dong Fang Wu,3 Zhong Mao Guo,1 Emmanuel Okoro,1 and Hong Yang1 ... 2, no. 5, pp. 113-120, 2010. View at Publisher · View at Google Scholar · View at Scopus ... 1-2, pp. 29-63, 2005. View at Publisher · View at Google Scholar · View at Scopus ... 2, pp. 395-405, 2008. View at Publisher · View at Google Scholar · View at Scopus ...
more infohttps://www.hindawi.com/journals/isrn/2013/847310/ref/
Qualitative differences in the spectra of genetic damage in 2-aminopurine-induced ad-3 mutants between nucleotide excision...  Qualitative differences in the spectra of genetic damage in 2-aminopurine-induced ad-3 mutants between nucleotide excision...
The mutagenic effects of 2-aminopurine (2AP) have been compared in the adenine-3 (ad-3) region of two-component heterokaryons ... uvs-2/uvs-2) heterokaryon 59 (H-59). This forward-mutation, morphological and biochemical, specific-locus assay ... The defect in DNA repair due to the uvs-2 allele, which has been shown to be a deficiency in pyrimidine dimer excision (Worthy ... The mutagenic effects of 2-aminopurine (2AP) have been compared in the adenine-3 (ad-3) region of two-component heterokaryons ...
more infohttps://www.rti.org/publication/qualitative-differences-spectra-genetic-damage-2-aminopurine-induced-ad-3-mutants
Electronic transition moments of 2-aminopurine  Electronic transition moments of 2-aminopurine
The electronic spectrum of the unnatural nucleic acid base 2-aminopurine is important in order to understand the spectroscopy ... the near-UV spectrum of 2-aminopurine is resolved into contributions from five electronic transitions. Four moderately strong ... moment directions and effective absorption components is also a prerequisite for the interpretation of emission spectra of 2- ... aminopurine incorporated into DNA as a probe of nucleic acid base motion or excitation energy transfer processes. Using linear ...
more infohttps://research.chalmers.se/en/publication/143447
Conformation Change of the Loop Adenine of Avian Leukosis Virus RNA Upon Antibiotic Binding Revealed by 2-Aminopurine...  Conformation Change of the Loop Adenine of Avian Leukosis Virus RNA Upon Antibiotic Binding Revealed by 2-Aminopurine...
I.Z. Shukshina2. 1Engelhardt Institute. of Molecular Biology. Russian Academy of Sciences. Moscow, 119991 Russia. 2Moscow ... To this end we replaced the unpaired adenine in the hairpin loop of avian leukosis virus RNA with a fluorescent probe 2- ... aminopurine (2-AP). This approach permitted us to discriminate between the local conformation of the unpaired adenine in ... It has also been found that the intensity of 2-AP fluorescence for the two RNA dimers is different. Significantly lower ...
more infohttps://www.jbsdonline.com/conformation-change-loop-adenine-of-avian-leukosis-virus-rna-upon-antibiotic-binding-revealed-2-aminopurine-fluorescence-p17300.html
Conformation Change of the Loop Adenine of Avian Leukosis Virus RNA Upon Antibiotic Binding Revealed by 2-Aminopurine...  Conformation Change of the Loop Adenine of Avian Leukosis Virus RNA Upon Antibiotic Binding Revealed by 2-Aminopurine...
I.Z. Shukshina2. 1Engelhardt Institute. of Molecular Biology. Russian Academy of Sciences. Moscow, 119991 Russia. 2Moscow ... To this end we replaced the unpaired adenine in the hairpin loop of avian leukosis virus RNA with a fluorescent probe 2- ... aminopurine (2-AP). This approach permitted us to discriminate between the local conformation of the unpaired adenine in ... It has also been found that the intensity of 2-AP fluorescence for the two RNA dimers is different. Significantly lower ...
more infohttp://www.jbsdonline.com/c3034/c4265/conformation-change-loop-adenine-of-avian-leukosis-virus-rna-upon-antibiotic-binding-revealed-2-aminopurine-fluorescence-p17300.html
DNA base stacking involving adenine and 2-aminopurine  DNA base stacking involving adenine and 2-aminopurine
... Item metadata. dc.contributor.author. van Mourik, Tanja. ... For each type of stack, between five and nine minima were located, usually connected by low barriers of 1-2 kcal/mol. This ... van Mourik , T & Hogan , S W L 2016 , ' DNA base stacking involving adenine and 2-aminopurine ' Structural Chemistry , vol. 27 ... The potential energy surfaces of stacked structures consisting of adenine (A) and 2-aminopurine (2AP) have been investigated in ...
more infohttps://research-repository.st-andrews.ac.uk/handle/10023/8230?show=full
Polbase - Reference: Using 2-aminopurine fluorescence to detect base unstacking in the template strand during nucleotide...  Polbase - Reference: Using 2-aminopurine fluorescence to detect base unstacking in the template strand during nucleotide...
Using 2-aminopurine fluorescence to detect base unstacking in the template strand during nucleotide incorporation by the ... Using 2-aminopurine fluorescence to detect base unstacking in the template strand during nucleotide incorporation by the ... The fluorescence of the base analogue 2-aminopurine (2AP) was used to detect physical changes in the template strand during ... The fluorescence of the base analogue 2-aminopurine (2AP) was used to ... ...
more infohttps://polbase.neb.com/references/99
Polbase - Reference: On the molecular basis of transition mutations. Frequency of forming 2-aminopurine-cytosine base mispairs...  Polbase - Reference: On the molecular basis of transition mutations. Frequency of forming 2-aminopurine-cytosine base mispairs...
2-aminopurine-cytosine base mispairs are reduced if next to a 5' primer thymine site and more prevalent if next to a 5' guanine ... The frequency of 2-aminopurine X cytosine base mispair formation in the G X C----A X T pathway is similar to that found ... Frequency of forming 2-aminopurine-cytosine base mispairs in the G X C----A X T mutational pathway by T4 DNA polymerase in ... 2-aminopurine-cytosine base mispairs are reduced if next to a 5' primer thymine site and more prevalent if next to a 5' guanine ...
more infohttps://polbase.neb.com/references/246
Seminars | Department of Chemistry  Seminars | Department of Chemistry
2. The development of new biomaterials via a general synthetic chemoselective redox responsive ligation (click) and release ...
more infohttp://www.chemistry.wustl.edu/taxonomy/term/5?page=29
Configurational diffusion down a folding funnel describes the dynamics of DNA hairpins | PNAS  Configurational diffusion down a folding funnel describes the dynamics of DNA hairpins | PNAS
2 where n(t) is the center of mass of the probability distribution as a function of time. n(t) at t = 0+ is assumed a δ- ... 2). Tf was determined from the ratio I(∞,Tf)/I(0−,Ti) calibrated on a fluorescence melting profile for each hairpin. The ... pdf). The discrete values of the free energies (at θI = 0, 1/6, 1/3, ½, 2/3, 5/6, and 1) are interpolated on a finer grid by ... Figure 2 Kinetics of unwinding/hairpin formation. The fluorescence of 2AP substituted at site 1 (hairpin H1) is monitored as a ...
more infohttps://www.pnas.org/content/98/14/7771?ijkey=2fc35a6bffc21f4fe511df36f0f712fdbbcb059c&keytype2=tf_ipsecsha
AZD7451 for Recurrent Gliomas - Full Text View - ClinicalTrials.gov  AZD7451 for Recurrent Gliomas - Full Text View - ClinicalTrials.gov
2) Determine the ionized calcium levels. Exclusion is then to be based on whether these ionized calcium levels are out of ... Patients must be at least 4 weeks from other cytotoxic therapies not listed above and 2 weeks for non-cytotoxic agents (e.g., ... A 12 lead electrocardiogram (ECG) to be performed within 2 weeks of trial entry with QTc less than or equal to 470 msec. ... In cases where the serum calcium is below the normal range, 2 options would be available: 1) the calcium adjusted for albumin ...
more infohttps://clinicaltrials.gov/ct2/show/NCT01468324
Famciclovir Pediatric Formulation in Children 1 to 12 Years of Age With Herpes Simplex Infection - Full Text View -...  Famciclovir Pediatric Formulation in Children 1 to 12 Years of Age With Herpes Simplex Infection - Full Text View -...
Time Frame: Administered 2 times daily over 7 days ]. A patient with multiple AEs within the primary system organ class is ... 2-Aminopurine. Antiviral Agents. Anti-Infective Agents. Antimetabolites. Molecular Mechanisms of Pharmacological Action. ... Apparent Oral Clearance of Penciclovir (CL/F) [ Time Frame: Plasma level measurements: pre-dose, 1, 2, 3, 4 and 5 hours post- ... Apparent Terminal Elimination Half-life of Penciclovir (T1/2) [ Time Frame: Plasma level measurements: pre-dose, 1, 2, 3, 4 and ...
more infohttps://clinicaltrials.gov/show/NCT00098059
1,3-dioxolanylpurine nucleosides (2R,4R) and (2R,4S) with selective anti-HIV-1 activity in human lymphocytes.  - PubMed - NCBI  1,3-dioxolanylpurine nucleosides (2R,4R) and (2R,4S) with selective anti-HIV-1 activity in human lymphocytes. - PubMed - NCBI
The decreasing antiviral activity order of beta-isomers was as follows: guanine , 6-chloro-2-aminopurine , 2-fluoroadenine , or ... and 2,6-dichloropurine in the presence of TMS triflate. The chloro or fluoro substituents were readily converted into amino, N- ... 2-chloroadenine , 6-chloropurine approximately equal to N6-methyladenine approximately equal to 6-mercaptopurine approximately ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed/8421287?dopt=Abstract
Part 2 - Session 1 | Coursera  Part 2 - Session 1 | Coursera
Now, the argument of Benzer is that if two amino purine. can induce either one or both of these transitions and make an active ... Part 2. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video ... Since ochre can be converted into amber by treatment with 2-aminopurine, a base analog mutagen, the two codons must have two ...
more infohttps://www.coursera.org/learn/papers-molecular-genetics/lecture/5F0bd/part-2
Part 2 - Session 7 | Coursera  Part 2 - Session 7 | Coursera
Now, the argument of Benzer is that if two amino purine can induce either one or both of these transitions and make an active ... Part 2. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video ... 2:15. And there are lots of other mutants in the R2A which are not ambivalent and ... 2:26. There is a slight little problem in the logic of the paper at that point. ...
more infohttps://www.coursera.org/lecture/papers-molecular-genetics/part-2-5F0bd
Waterloo Institute for Nanotechnology  Waterloo Institute for Nanotechnology
2-Aminopurine-modified DNA homopolymers for robust and sensitive detection of mercury and silver  Zhou, Wenhu; Ding, Jinsong; ... A highly specific sodium aptamer probed by 2-aminopurine for robust Na+ sensing  Zhou, Wenhu; Ding, Jinsong; Liu, Juewen ( ...
more infohttps://uwspace.uwaterloo.ca/handle/10012/11339
  • A 5-fold reduction in proofreading frequency occurs when the mispair is formed with 2-aminopurine deoxynucleoside monophosphate stacked adjacent to a 5'-primer guanine. (neb.com)
  • Frequency of forming 2-aminopurine-cytosine base mispairs in the G X C----A X T mutational pathway by T4 DNA polymerase in vitro. (neb.com)
  • The frequency of inserting 2-aminopurine deoxyribonucleoside monophosphate in place of dGMP opposite template cytosine sites is about 3-6% when either strong or weak base-stacking partners are present on the primer strand. (neb.com)
  • The frequency of 2-aminopurine X cytosine base mispair formation in the G X C----A X T pathway is similar to that found previously in the A X T----G X C pathway (Watanabe, S. M., and Goodman, M.F. (1981) Proc. (neb.com)
  • In addition, quantitative differences were also found between the spectra of ad-3 mutations in 1 subclass of multiple-locus mutations, but not 2 additional subclasses. (rti.org)
  • 2-Aminopurine inhibits lipid accumulation induced by apolipoprotein E-deficient lipoprotein in macrophages: potential role of eukaryotic initiation factor-2 α phosphorylation in foam cell formation," Journal of Pharmacology and Experimental Therapeutics , vol. 326, no. 2, pp. 395-405, 2008. (hindawi.com)
  • Apolipoprotein E-deficient lipoproteins induce foam cell formation by activation of PERK-EIF-2 α signaling cascade," Journal of Bioanalysis and Biomedicine , vol. 2, no. 5, pp. 113-120, 2010. (hindawi.com)
  • J. Lewerenz and P. Maher, "Basal levels of eIF2 α phosphorylation determine cellular antioxidant status by regulating ATF4 and xCT expression," Journal of Biological Chemistry , vol. 284, no. 2, pp. 1106-1115, 2009. (hindawi.com)
  • 2. A pharmaceutical composition comprising the compound of claim 1 and a pharmaceutically acceptable carrier. (google.com)
  • The enantiomerically pure key intermediate 1, which was synthesized in nine steps from 1,6-anhydro-beta-D-mannose, was condensed with 6-chloropurine, 6-chloro-2-fluoropurine, and 2,6-dichloropurine in the presence of TMS triflate. (nih.gov)
  • This result implies that 2-AP loses the initial intra-loop interactions in the structure KD on interaction with tobramycin, becoming more exposed into the solution that is reflected in its fluorescence increase. (jbsdonline.com)