Polymer grafted recyclable magnetic nanoparticles

The recyclable poly(methacrylic acid) grafted magnetic particles retained excellent aqueous phase dispersibility and high biological activity against bacteria when loaded with an antibiotic. The particles were removed from water solutions using a magnet after antimicrobial testing, thus avoiding nano-based pollution of the biological environment.

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Immobilization of Papain on Flexible Magnetic Nanoparticles

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.723.511 ◽

2015 ◽

Vol 723 ◽

pp. 511-514

Author(s):

Lian Tan ◽

Lan Qian Li ◽

Jing Dong ◽

Zu Lan Liu ◽

Yi Ping Liu ◽

...

Keyword(s):

Fourier Transform ◽

Biological Activity ◽

Magnetic Nanoparticles ◽

Potential Application ◽

Magnetic Particles ◽

Immobilized Enzyme ◽

Dialdehyde Starch ◽

Medium Ph ◽

Food Industries ◽

Negative Effect

Flexible magnetic nanoparticles decorated with dialdehyde starch (DAS) were developed and used as a novel enzyme support for the covalent conjugation of papain. The analyses of Fourier transform infrared (FTIR) spectroscopy confirmed the preparation of magnetic particles with flexible long molecular chains on their surfaces and conjugation of papain with the Fe3O4-DAS nanoparticles. Considering that the immobilized papain was found to exhibit better tolerance to the variations of temperature and medium pH, an advantage of easy to magnetic separation and lack of negative effect on biological activity, the kind of flexible magnetic bioconjugate support should be a good immobilized enzyme carrier, and has potential application in textile, leather, food industries.

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A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v12i1.845 ◽

2015 ◽

Vol 12 (1) ◽

pp. 3910-3918 ◽

Cited By ~ 1

Author(s):

Dr Remon M Zaki ◽

Prof Adel M. Kamal El-Dean ◽

Dr Nermin A Marzouk ◽

Prof Jehan A Micky ◽

Mrs Rasha H Ahmed

Keyword(s):

Biological Activity ◽

Carbonyl Compounds ◽

Mass Spectra ◽

The Other ◽

Pyridine Derivatives ◽

Facile Synthesis ◽

High Biological Activity ◽

Basic Hydrolysis ◽

Pyridine Carboxylate ◽

Hydrolysis Of

Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.

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The Psychonauts’ Benzodiazepines; Quantitative Structure-Activity Relationship (QSAR) Analysis and Docking Prediction of Their Biological Activity

Pharmaceuticals ◽

10.3390/ph14080720 ◽

2021 ◽

Vol 14 (8) ◽

pp. 720

Author(s):

Valeria Catalani ◽

Michelle Botha ◽

John Martin Corkery ◽

Amira Guirguis ◽

Alessandro Vento ◽

...

Keyword(s):

Biological Activity ◽

Computational Models ◽

Quantitative Structure Activity Relationship ◽

Structure Activity Relationship ◽

Docking Studies ◽

Health Concern ◽

Activity Relationship ◽

Quantitative Structure ◽

High Biological Activity ◽

Structure Activity

Designer benzodiazepines (DBZDs) represent a serious health concern and are increasingly reported in polydrug consumption-related fatalities. When new DBZDs are identified, very limited information is available on their pharmacodynamics. Here, computational models (i.e., quantitative structure-activity relationship/QSAR and Molecular Docking) were used to analyse DBZDs identified online by an automated web crawler (NPSfinder®) and to predict their possible activity/affinity on the gamma-aminobutyric acid A receptors (GABA-ARs). The computational software MOE was used to calculate 2D QSAR models, perform docking studies on crystallised GABA-A receptors (6HUO, 6HUP) and generate pharmacophore queries from the docking conformational results. 101 DBZDs were identified online by NPSfinder®. The validated QSAR model predicted high biological activity values for 41% of these DBDZs. These predictions were supported by the docking studies (good binding affinity) and the pharmacophore modelling confirmed the importance of the presence and location of hydrophobic and polar functions identified by QSAR. This study confirms once again the importance of web-based analysis in the assessment of drug scenarios (DBZDs), and how computational models could be used to acquire fast and reliable information on biological activity for index novel DBZDs, as preliminary data for further investigations.

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Replacement of the interchain disulfide bridge-forming amino acids A7 and B7 by glutamate impairs the structure and activity of insulin

Biological Chemistry ◽

10.1515/bc.2004.151 ◽

2004 ◽

Vol 385 (12) ◽

pp. 1171-1175 ◽

Cited By ~ 7

Author(s):

Zhan-Yun Guo ◽

Xiao-Yuan Jia ◽

You-Min Feng

Keyword(s):

Biological Activity ◽

Disulfide Bonds ◽

Negative Charge ◽

Disulfide Bridge ◽

Site Directed Mutagenesis ◽

Side Chain ◽

Insulin Analogs ◽

High Biological Activity ◽

Chemical Groups ◽

Structure And Activity

Abstract Insulin contains three disulfide bonds, one intrachain bond, A6–A11, and two interchain bonds, A7–B7 and A20–B19. Site-directed mutagenesis results (the two cysteine residues of disulfide A7–B7 were replaced by serine) showed that disulfide A7–B7 is crucial to both the structure and activity of insulin. However, chemical modification results showed that the insulin analogs still retained relatively high biological activity when A7Cys and B7Cys were modified by chemical groups with a negative charge. Did the negative charge of the modification groups restore the loss of activity and/or the disturbance of structure of these insulin analogs caused by deletion of disulfide A7–B7? To answer this question, an insulin analog with both A7Cys and B7Cys replaced by Glu, which has a long side-chain and a negative charge, was prepared by protein engineering, and its structure and activity were analyzed. Both the structure and activity of the present analog are very similar to that of the mutant with disulfide A7–B7 replaced by Ser, but significantly different from that of wild-type insulin. The present results suggest that removal of disulfide A7–B7 will result in serious loss of biological activity and the native conformation of insulin, even if the disulfide is replaced by residues with a negative charge.

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Useful Oriented Immobilization of Antibodies on Chimeric Magnetic Particles: Direct Correlation of Biomacromolecule Orientation with Biological Activity by AFM Studies

Langmuir ◽

10.1021/la502972v ◽

2014 ◽

Vol 30 (49) ◽

pp. 15022-15030 ◽

Cited By ~ 9

Author(s):

Marzia Marciello ◽

Marco Filice ◽

David Olea ◽

Marisela Velez ◽

José M. Guisan ◽

...

Keyword(s):

Biological Activity ◽

Magnetic Particles ◽

Oriented Immobilization

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Molecular Evolution Allows Bypass of the Requirement for Activation Loop Phosphorylation of the Cdc28 Cyclin-Dependent Kinase

Molecular and Cellular Biology ◽

10.1128/mcb.18.5.2923 ◽

1998 ◽

Vol 18 (5) ◽

pp. 2923-2931 ◽

Cited By ~ 33

Author(s):

Frederick R. Cross ◽

Kristi Levine

Keyword(s):

Cell Cycle ◽

Biological Activity ◽

Cell Cycle Progression ◽

Dna Amplification ◽

Protein Kinase Activity ◽

Activation Loop ◽

Cyclin Dependent Kinase ◽

High Biological Activity ◽

Cycle Progression ◽

Growth Defects

ABSTRACT Many protein kinases are regulated by phosphorylation in the activation loop, which is required for enzymatic activity. Glutamic acid can substitute for phosphothreonine in some proteins activated by phosphorylation, but this substitution (T169E) at the site of activation loop phosphorylation in the Saccharomyces cerevisiae cyclin-dependent kinase (Cdk) Cdc28p blocks biological function and protein kinase activity. Using cycles of error-prone DNA amplification followed by selection for successively higher levels of function, we identified mutant versions of Cdc28p-T169E with high biological activity. The enzymatic and biological activity of the mutant Cdc28p was essentially normally regulated by cyclin, and the mutants supported normal cell cycle progression and regulation. Therefore, it is not a requirement for control of the yeast cell cycle that Cdc28p be cyclically phosphorylated and dephosphorylated. TheseCDC28 mutants allow viability in the absence of Cak1p, the essential kinase that phosphorylates Cdc28p-T169, demonstrating that T169 phosphorylation is the only essential function of Cak1p. Some growth defects remain in suppressed cak1 cdc28 strains carrying the mutant CDC28 genes, consistent with additional nonessential roles for CAK1.

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Influence of Magnetic Nanoparticles on PISA Preparation of Poly(Methacrylic Acid)-b -Poly(Methylmethacrylate) Nano-Objects

Macromolecular Rapid Communications ◽

10.1002/marc.201800333 ◽

2018 ◽

Vol 40 (2) ◽

pp. 1800333 ◽

Cited By ~ 7

Author(s):

Lakshmeesha Upadhyaya ◽

Chidubem Egbosimba ◽

Xianghong Qian ◽

Ranil Wickramasinghe ◽

Rodrigo Fernández-Pacheco ◽

...

Keyword(s):

Magnetic Nanoparticles ◽

Methacrylic Acid

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Multicomponent Mandibular Gland Secretions in Three Species of Andrena Bees (Hym., Apoidea)

Zeitschrift für Naturforschung C ◽

10.1515/znc-1982-11-1213 ◽

1982 ◽

Vol 37 (11-12) ◽

pp. 1124-1129 ◽

Cited By ~ 28

Author(s):

Gunnar Bergström ◽

Jan Tengö ◽

Wolfgang Reith ◽

Wittko Francke

Keyword(s):

Biological Activity ◽

Mandibular Gland ◽

Point Of View ◽

Straight Chain ◽

High Biological Activity ◽

Quantitative Distribution ◽

Males And Females ◽

Distribution Of Components ◽

Minor Concentration ◽

Mandibular Gland Secretions

Abstract 50 volatile constituents of the mandibular gland secretions in males and females of three species of Andrena bees, A. wilkella (Chr.), A. ovatula (K .) and A. ocreata (K .), have been identified. The secretions are made up of a series of spiroacetals of four different systems together with mono-terpenes and unbranched acyclic compounds. Many of the components, particularly several of the dominant ones, occur in both sexes of all three species, so that the volatile secretions are qualitatively very similar. Females contain about 100 μg per individuum , which is 3-5 times the amount of the males’ secretions. Major spiroacetals are E,E- and Z ,E-2,8-dimethyl-1,7-dioxa-spiro[5.5]undecane and E,E-and Z,E-2-ethyl-7-methyl-1,6-dioxaspiro[4.5]undecane, while prominent monoterpenes are geraniol and citronellol. Straight chain hydrocarbons C17, C19, C21 and C23 occur in fairly large amounts, mostly with increasing concentrations. With respect to the quantitative distribution of components of minor concentration, the bouquet of A. wilkella is clearly distinguishable from A. ovatula and A. ocreata which from the morphological and ethological point of view are more closely related. Behaviour tests with A. wilkella indicate high biological activity of the main spiroacetal.

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