54 research outputs found

    Spinning Pulsating String Solitons in AdS_5 x S^5

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    We point out the existence of some simple string solitons in AdS_5 x S^5, which at the same time are spinning in AdS_5 and pulsating in S^5, or vice-versa. This introduces an additional arbitrary constant into the scaling relations between energy and spin or R-charge. The arbitrary constant is not an angular momentum, but can be related to the amplitude of the pulsation. We discuss the solutions in detail and consider the scaling relations. Pulsating multi spin or multi R-charge solutions can also be constructed.Comment: 15 pages, Late

    Spinning and rotating strings for N=1 SYM theory and brane constructions

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    We obtain spinning and rotating closed string solutions in AdS_5 \times T^{1,1} background, and show how these solutions can be mapped onto rotating closed strings embedded in configurations of intersecting branes in type IIA string theory. Then, we discuss spinning closed string solutions in the UV limit of the Klebanov-Tseytlin background, and also properties of classical solutions in the related intersecting brane constructions in the UV limit. We comment on extensions of this analysis to the deformed conifold background, and in the corresponding intersecting brane construction, as well as its relation to the deep IR limit of the Klebanov-Strassler solution. We briefly discuss on the relation between type IIA brane constructions and their related M-theory descriptions, and how solitonic solutions are related in both descriptions.Comment: 35 pages. Dedicated to the memory of Ian I. Kogan. References adde

    On the Classical String Solutions and String/Field Theory Duality

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    We classify almost all classical string configurations, considered in the framework of the semi-classical limit of the string/gauge theory duality. Then, we describe a procedure for obtaining the conserved quantities and the exact classical string solutions in general string theory backgrounds, when the string embedding coordinates depend non-linearly on the worldsheet time parameter.Comment: LaTeX, 15 pages, no figures; V2: some typos corrected; V3: no corrections, to appear in JHE

    Физико-химические свойства мутантных форм L-аспарагиназы из Rhodospirillum rubrum, обладающих антителомеразной активностью

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    Rru_A3730 protein is a bacterial Rhodospirillum rubrum L-asparaginase (RrA), which is known by its anticancer activity. RrA variants with point amino acid substitutions in the region of 150 amino acids residues: RrA17N, K149E, RrAE149R, V150P, F151T, RrА17N, E149R, V150P, RrAE149R, V150P, showed antiproliferative properties, and also by their ability to suppress telomerase activity. This work is devoted to comparison of physical-chemical and catalytic properties of these mutant forms of RrA. It is shown that pH optimum is in the alkaline zone (8.5 – 9.3); L-glutaminase and D-asparaginase activity is respectively not more than 0.1% and 1.6% of L-asparaginase for all studied variants of RrA. The presence of the N17-terminal amino acid sequence MASMTGGQMGRGSSRQ of the capsid protein of bacteriophage T7 in the RrA structure leads to an increase in the thermal stability of mutant RrA analogues (from 50°C to 56°C) and their resistance to denaturation in the presence of 3 – 4 M urea. It is of Metal ions exhibit multidirectional effects on L-asparaginase activity of RrA. K+, Ca2+, Zn2+, Cs+, Co2+ in significantly affect the activity of L-asparaginase, while Mn2+, Cu2+, Fe3+ ions inhibit it. There was no correlation between antitelomerase (antiproliferative) activity and kinetic properties of mutant forms of L-asparaginase RrA.Белок Rru_A3730, известный как бактериальная L-аспарагиназа Rhodospirillum rubrum, представляет интерес в качестве потенциального противоопухолевого средства, особенно её варианты с точечными аминокислотными заменами в районе 150 аминокислотного остатка (а.к.о.): RrA17N, K149E, RrAE149R, V150P, F151T, RrА17N, E149R, V150P, RrAE149R, V150P, обладающие не только антипролиферативными свойствами, но и способностью подавлять активность теломеразы. Данная работа посвящена сравнению физико-химических и каталитических свойств этих мутантных форм RrA. Показано, что для всех изученных вариантов RrA рН оптимум находится в щелочной зоне (8.5 – 9.3); L-глутаминазная и D-аспарагиназная активность составляют, соответственно, не более 0.1% и 1.6% от L-аспарагиназной. Присутствие 17N-концевой аминокислотной последовательности MASMTGGQQMGRGSSRQ капсидного белка бактериофага Т7 в структуре RrA приводит к повышению термостабильности мутантных аналогов RrA (от 50°С до 56°С) и их устойчивости к денатурации в присутствии 3 – 4 М мочевины. Выявлен разнонаправленный эффект ионов металлов на L-аспарагиназную активность вариантов RrA: ионы K+, Ca2+, Zn2+, Cs+, Co2+ существенно не влияют на активность L-аспарагиназы, добавление ионов Mn2+, Cu2+, Fe3+ приводит к снижению активности. Не обнаружено корреляции между антителомеразной (антипролиферативной) активностью и кинетическими свойствами мутантных форм L-аспарагиназы RrA

    Multi-spin strings on AdS(5)xT(1,1) and operators of N=1 superconformal theory

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    We study rotating strings with multiple spins in the background of AdS5×T1,1AdS_5\times T^{1,1}, which is dual to a N=1\mathcal{N}=1 superconformal field theory with global symmetry SU(2)×SU(2)×U(1)SU(2)\times SU(2)\times U(1) via the AdS/CFT correspondence. We analyse the limiting behaviour of macroscopic strings and discuss the identification of the dual operators and how their anomalous dimensions should behave as the global charges vary. A class of string solutions we find are dual to operators in SU(2) subsector, and our result implies that the one-loop planar dilatation operator restricted to the SU(2) subsector should be equivalent to the hamiltonian of the integrable Heisenberg spin chain.Comment: 8 pages, revtex4, twocolum

    Molecular Analysis of L-Asparaginases for Clarification of the Mechanism of Action and Optimization of Pharmacological Functions

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    L-asparaginases (EC 3.5.1.1) are a family of enzymes that catalyze the hydrolysis of L-asparagine to L-aspartic acid and ammonia. These proteins with different biochemical, physico-chemical and pharmacological properties are found in many organisms, including bacteria, fungi, algae, plants and mammals. To date, asparaginases from E. coli and Dickeya dadantii (formerly known as Erwinia chrysanthemi) are widely used in hematology for the treatment of lymphoblastic leukemias. However, their medical use is limited by side effects associated with the ability of these enzymes to hydrolyze L-glutamine, as well as the development of immune reactions. To solve these issues, gene-editing methods to introduce amino-acid substitutions of the enzyme are implemented. In this review, we focused on molecular analysis of the mechanism of enzyme action and to optimize the antitumor activity. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
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