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91.
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Villareal V Kaddis J Azad M Zurita C Silva I Hernandez L Rudolph M Moran J Gomez FA 《Analytical and bioanalytical chemistry》2003,376(6):822-831
Partial-filling affinity capillary electrophoresis (PFACE) is used to examine the binding interactions between two model biological systems: D-Ala-D-Ala terminus peptides to the glycopeptide antibiotic vancomycin (Van) from Streptomyces orientalis, and arylsulfonamides to carbonic anhydrase B (CAB, EC 4.2.1.1, bovine erythrocytes). Using these two systems, modifications in the PFACE technique are demonstrated including flow-through PFACE (FTPFACE), competitive flow-through PFACE (CFTPFACE), on-column ligand synthesis PFACE (OCLSPFACE), and multiple-step ligand injection PFACE (MSLIPFACE). In PFACE small plugs of sample are injected into the capillary column and an equilibrium is established between receptor and ligand during electrophoresis. Binding constants are then obtained by Scatchard analysis using changes in the migration time of the receptor/ligand on changing the concentration of the ligand/receptor. Data demonstrating the quantitative potential of these methods are presented. This review focuses on the unique capabilities of the different PFACE techniques as applied to two model biological systems. 相似文献
94.
Russell G. Baughman Daniel J. Brink Jill M. Butler Pamela R. New 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):528-531
The first single‐crystal studies of three bis‐transoid Cu–hydroxamate salts, bis(3‐methoxy‐4,N‐dimethylbenzohydroxamato‐O,O′)copper(II), [Cu(C10H12NO3)2], bis(4‐chloro‐N‐methylbenzohydroxamato‐O,O′)copper(II), [Cu(C8H7ClNO2)2], bis(N‐methyl‐3,5‐dinitrobenzohydroxamato‐O,O′)copper(II)–chloroform (1/2), [Cu(C8H6N3O6)2]·2CHCl3, are presented. The Cu atom in each of the title compounds sits at a center of inversion and displays a nearly square‐planar geometry with the hydroxamate‐O atoms connected to it in a syn configuration. The N atoms are in a transoid configuration. Each five‐membered Cu–hydroxamate ring is planar, thus providing evidence that a planar N atom is present in each ring. The phenyl groups are twisted with respect to the hydroxamate group by ~40–54°. The angular strain of the sp2 carbonyl oxygen is significant (~10° from ideal). 相似文献
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Abeer F. Shunnar Dr. Bhausaheb Dhokale Dr. Durga Prasad Karothu David H. Bowskill Dr. Isaac J. Sugden Dr. Hector H. Hernandez Prof. Panče Naumov Dr. Sharmarke Mohamed 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(21):4752-4765
The discovery of molecular ionic cocrystals (ICCs) of active pharmaceutical ingredients (APIs) widens the opportunities for optimizing the physicochemical properties of APIs whilst facilitating the delivery of multiple therapeutic agents. However, ICCs are often observed serendipitously in crystallization screens and the factors dictating their crystallization are poorly understood. We demonstrate here that mechanochemical ball milling is a versatile technique for the reproducible synthesis of ternary molecular ICCs in less than 30 min of grinding with or without solvent. Computational crystal structure prediction (CSP) calculations have been performed on ternary molecular ICCs for the first time and the observed crystal structures of all the ICCs were correctly predicted. Periodic dispersion-corrected DFT calculations revealed that all the ICCs are thermodynamically stable (mean stabilization energy=−2 kJ mol−1) relative to the crystallization of a physical mixture of the binary salt and acid. The results suggest that a combined mechanosynthesis and CSP approach could be used to target the synthesis of higher-order molecular ICCs with functional properties. 相似文献
97.
Robert Moglia Michael Whitely Megan Brooks Jennifer Robinson Michael Pishko Elizabeth Cosgriff‐Hernandez 《Macromolecular rapid communications》2014,35(14):1301-1305
The growth factor bone morphogenetic protein 2 (BMP‐2) is utilized in surgical procedures to improve bone regeneration; however, current treatments deliver BMP‐2 at amounts greater than 100 000 fold of physiological levels, which increases treatment costs and risk of side effects. Drug‐eluting microcarriers developed to improve these therapies have faced significant commercialization challenges including particle size distributions, solvent removal, low encapsulation efficiency, and bioactivity loss. In this study, a solvent‐free method is presented for fabrication of uniform polyHIPE microspheres for controlled growth factor release. Emulsion templating principles and fluid dynamics were used to fabricate uniform particles with tunable particle size (200–800 μm) and pore size (10–30 μm). The ability to independently tune particle and pore size is expected to provide excellent control of release kinetics. Overall, this solvent‐free method for making porous microspheres displays strong promise for the controlled release of BMP‐2 and other growth factors.
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99.
Lamoureux M Patard L Hernandez B Couesnon T Santini GP Cognet JA Gouyette C Cordier C 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,65(1):84-94
Successive investigations over the last decade have revealed and confirmed a stable loop closure in a family of d-[GTAC-5Pur6N7N-GTAC] hairpins, where 5Pur6N7N is a AAA, GAG and AXC loop (X being any nucleotide). The trinucleotide loop is characterized by a well defined 5Pur-7N mispairing mode, and by upfield chemical shifts for three sugar protons of the apical nucleotide 6N. The GTTC-ACA-GAAC DNA hairpin, of interest for its likely involvement in Vibrio cholerae genome mutations, has now been investigated. The GTAC-ACA-GTAC DNA hairpin has also been studied because it is intermediate between the other structures, as it contains the loop of the hairpin under consideration and the stem of the above family. The two hairpins with the ACA loop are stable. They show the same mispairing mode and similar upfield shifts as the previous family, but GTTC-ACA-GAAC seems to be slightly less compact than any other. GTTC-ACA-GAAC is remarkable in that it exhibits a B(II) character for the phosphate-ester conformation at 8Gp9A, together with a swing of the upper hairpin into the major groove that, in particular, brings 6CH1' roughly as close to 7AH2 as to 6CH6. These unexpected structural features are qualitatively deduced from (1)H and (31)P NMR spectra, and confirmed by Raman spectroscopy. This comparative study shows that not only the loop sequence but also the stem sequence may control hairpin structures. 相似文献
100.
Hunt CE Pasetto P Ansell RJ Haupt K 《Chemical communications (Cambridge, England)》2006,(16):1754-1756
The first pseudo-immunoassay which employs a molecularly imprinted receptor and a fluorescent probe, and quantifies the bound analyte directly using the fluorescence anisotropy of the polymer-probe-analyte suspension, is described. 相似文献