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Kubik S, Höller O, Steinert A, Tolksdorf M, Wulff G. Inclusion compounds of derivatized amyloses. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/masy.19950990111] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Rodriguez-Docampo Z, Eugenieva-Ilieva E, Reyheller C, Belenguer AM, Kubik S, Otto S. Dynamic combinatorial development of a neutral synthetic receptor that binds sulfate with nanomolar affinity in aqueous solution. Chem Commun (Camb) 2011; 47:9798-800. [DOI: 10.1039/c1cc13451e] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Taber-Doughty T, Shurr J, Brewer J, Kubik S. Standard care and telecare services: comparing the effectiveness of two service systems with consumers with intellectual disabilities. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2010; 54:843-859. [PMID: 20712698 DOI: 10.1111/j.1365-2788.2010.01314.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
BACKGROUND Onsite standard care and remote telecare supports were provided to adults with intellectual disabilities living in integrated community settings and evaluated in terms of effectiveness as consumers completed a series of novel household activities. METHODS Using an alternating treatment design with baseline and follow-up conditions in this single-case study, investigators compared the prompting effectiveness provided by onsite standard care staff and a remote telecare provider. RESULTS While both types of supports resulted in consumers completing tasks, results indicated consumers achieved slightly more independence when prompted by the telecare support provider. Additionally, telecare supports resulted in greater duration for task completion per consumer. CONCLUSIONS Although consumers completed tasks with greater independence using telecare supports, caution should be used when interpreting results due to the small number of participants. The potential for this technology certainly exists in supporting consumers in their own homes thus, suggestions for future investigations are provided.
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Fiehn T, Goddard R, Seidel R, Kubik S. A Cyclopeptide-Derived Molecular Cage for Sulfate Ions That Closes with a Click. Chemistry 2010; 16:7241-55. [DOI: 10.1002/chem.201000308] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Krause MR, Goddard R, Kubik S. Formation of a cyclic tetrapeptide mimic by thermal azide–alkyne 1,3-dipolar cycloaddition. Chem Commun (Camb) 2010; 46:5307-9. [DOI: 10.1039/c0cc01154a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kubik S, Banfai P, Wachsmuth C. Comparison of Cochlear Histopathology Following Different Approaches in Guinea Pigs and Findings Gained by Regeneration Material in Humans. Acta Otolaryngol 2009. [DOI: 10.3109/00016488409099546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Hortmann G, Banfai P, Kubik S. Implanted Material Description. Acta Otolaryngol 2009. [DOI: 10.3109/00016488409099538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kubik S, Banfai P, Wachsmuth CH. Comparison of Cochlear Histopathology Following Different Approaches in Guinea Pigs and Findings Gained by Regeneration Material in Humans. Acta Otolaryngol 2009. [DOI: 10.3109/00016488409129738] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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60
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Kubik S, Métry IM. Eyepiece for Localisation of Drilling Holes. Acta Otolaryngol 2009. [DOI: 10.3109/00016488409099539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Reyheller C, Kubik S. Selective Sensing of Sulfate in Aqueous Solution Using a Fluorescent Bis(cyclopeptide). Org Lett 2007; 9:5271-4. [DOI: 10.1021/ol702386e] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kubik S, Miyashita T, Guzowski JF. Using immediate-early genes to map hippocampal subregional functions. Learn Mem 2007; 14:758-70. [DOI: 10.1101/lm.698107] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Rodriguez-Docampo Z, Pascu SI, Kubik S, Otto S. Noncovalent interactions within a synthetic receptor can reinforce guest binding. J Am Chem Soc 2007; 128:11206-10. [PMID: 16925439 DOI: 10.1021/ja062389h] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Structural and thermodynamic data are presented on the binding properties of anion receptors containing two covalently linked cyclopeptide subunits that bind sulfate and iodide anions with micromolar affinity in aqueous solution. A synchrotron X-ray crystal structure of the sulfate complex of one receptor revealed that the anion is bound between the peptide rings of the biscyclopeptide. Intimate intramolecular contacts between the nonpolar surfaces of the proline rings of the individual receptor moieties in the complex suggest that hydrophobic interactions within the receptor that do not directly involve the guest contribute to complex stability. This finding is supported by a microcalorimetric analysis of the solvent dependence of complex stability, which showed that increasing the water content of the solvent has only a weak influence on the Gibbs energy of binding. Hence, the increasing amount of energy required for desolvating the binding partners in solutions containing more water is almost compensated by the increasingly favorable hydrophobic interactions. Further observations that suggest that guest-induced intra-receptor interactions contribute to guest binding are (i) anion binding of a monomeric cyclopeptide lacking the covalent linkage between the two rings leads to the formation of 2:1 complexes; (ii) in the crystal structure of the 2:1 iodide complex of this monotopic receptor, a similar arrangement of the two cyclopeptide rings has been found as in the sulfate complex of the biscyclopeptide; (iii) complex formation of the monomeric cyclopeptide in aqueous solution is highly cooperative with a large stability constant corresponding to the formation of the 2:1 complexes from relatively instable 1:1 complexes; (iv) the monomeric cyclopeptide forms only 1:1 anion complexes in DMSO where hydrophobic interactions do not take place; and (v) introducing polar hydroxy groups on the proline rings of the monomeric cyclopeptide disrupts cooperativity causing the formation of only 1:1 complexes even in aqueous solution. Taken together these observations demonstrate that, in addition to direct receptor-substrate interactions, noncovalent interactions between the two subunits of such biscyclopeptides contribute significantly to anion complex stability. Reinforcement of molecular recognition through intra-receptor interactions should be an attractive new strategy to boost host-guest affinities.
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Kubik S, Strerath M, Meng M. Facile One-Step Synthesis of Mono-2-(p-Tolylsulfonyl)-β-cyclodextrin under Aqueous Conditions. SYNTHESIS-STUTTGART 2007. [DOI: 10.1055/s-2007-965885] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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69
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Reyheller C, Hay BP, Kubik S. Influence of linker structure on the anion binding affinity of biscyclopeptides. NEW J CHEM 2007. [DOI: 10.1039/b706932d] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Heinrichs G, Schellenträger M, Kubik S. An Enantioselective Fluorescence Sensor for Glucose Based on a Cyclic Tetrapeptide Containing Two Boronic Acid Binding Sites. European J Org Chem 2006. [DOI: 10.1002/ejoc.200600245] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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71
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Kubik S, Reyheller C, Stüwe S. Recognition of Anions by Synthetic Receptors in Aqueous Solution. J INCL PHENOM MACRO 2005. [DOI: 10.1007/s10847-005-0601-6] [Citation(s) in RCA: 200] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ahmad F, Constabel F, Geckeler KE, Seeck OH, Seo YS, Satija SK, Kubik S, Shin K. X-ray reflectivity study of cyclic peptide monolayers at the air-water interface. Isr J Chem 2005. [DOI: 10.1560/4qgd-xf09-a2r6-7np6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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73
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Kubik S, Goddard R, Otto S, Pohl S, Reyheller C, Stüwe S. Optimization of the binding properties of a synthetic anion receptor using rational and combinatorial strategies. Biosens Bioelectron 2005; 20:2364-75. [PMID: 15797340 DOI: 10.1016/j.bios.2004.01.035] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2003] [Revised: 01/07/2004] [Accepted: 01/07/2004] [Indexed: 11/19/2022]
Abstract
The solution conformations of tetrameric and hexameric cyclopeptides containing alternating L-proline and 6-aminopicolinic acid subunits strongly depend on solvent polarity. Whereas in polar solvents, such as d6-DMSO, both peptides prefer on average symmetric conformations with converging NH groups, in less polar chloroform intramolecular hydrogen bonds to the peptide NH groups stabilize other, and in the case of the hexapeptide, non-symmetrical conformations. Independent of the solvent, both peptides interact with anions via their NH groups but whereas anion binding requires a cleavage of the intramolecular hydrogen bonds accompanied by a conformational reorganization in chloroform, in polar solvents the peptides are already well preorganized for anion complexation. Complex formation between anions and the cyclic hexapeptide was even detected in highly competitive D2O/CD3OD or H2O/CH3CN mixtures, which was attributed to the special sandwich-type structure of the complexes formed. Stabilizing these 2:1 aggregates by covalently linking two cyclopeptide rings together affords ditopic receptors with a high anion affinity in protic solvents. Complex stability depends on the structure of the linker with which the two receptor moieties are connected and even more potent anion receptors were obtained by a dynamic combinatorial optimization of this linking unit.
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Heinrichs G, Kubik S, Lacour J, Vial L. Matched/Mismatched Interaction of a Cyclic Hexapeptide with Ion Pairs Containing Chiral Cations and Chiral Anions. J Org Chem 2005; 70:4498-501. [PMID: 15903331 DOI: 10.1021/jo050215x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The binding of a chiral quaternary ammonium ion to a cyclopeptide containing aromatic amino acid subunits is affected not only by the configuration of the cation but also by the configuration of the chiral counterion. Analysis of the binding equilibria shows that complex formation involves interaction of the whole ion pair with the host indicating that steric requirements of the anion influence complex geometry and stability.
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Otto S, Kubik S. Dynamic combinatorial optimization of a neutral receptor that binds inorganic anions in aqueous solution. J Am Chem Soc 2003; 125:7804-5. [PMID: 12822990 DOI: 10.1021/ja0351589] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A dynamic combinatorial library of potential anion receptors was generated from a cyclic peptide disulfide dimer and a series of dithiol spacers. Exposing the library to KI or K2SO4 led to the amplification of two new neutral receptors that bind anions through hydrogen bonding with up to micromolar affinity in aqueous solution. Thermodynamic studies suggest that these second-generation receptors outclass the previously described first-generation receptor, largely as a result of a more favorable enthalpy of binding. These results demonstrate that dynamic combinatorial optimization of designed hosts can be a powerful strategy, bringing synthetic receptors that approach the efficiencies of proteins one step closer.
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Heinrichs G, Vial L, Lacour J, Kubik S. Enantioselective recognition of a chiral quaternary ammonium ion by C3 symmetric cyclic hexapeptides. Chem Commun (Camb) 2003:1252-3. [PMID: 12809216 DOI: 10.1039/b302092d] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
C3 Symmetric cyclic hexapeptides containing alternating L-proline and 3-aminobenzoic acid derivatives as subunits possess different affinities towards the two enantiomers of the N,N,N-trimethyl-1-phenylethyl ammonium cation.
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Kubik S, Kirchner R, Nolting D, Seidel J. A molecular oyster: a neutral anion receptor containing two cyclopeptide subunits with a remarkable sulfate affinity in aqueous solution. J Am Chem Soc 2002; 124:12752-60. [PMID: 12392422 DOI: 10.1021/ja026996q] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An artificial anion receptor is presented, in which two cyclohexapeptide subunits containing l-proline and 6-aminopicolinic acid subunits in an alternating sequence are connected via an adipinic acid spacer. This compound was devised to stabilize the 2:1 sandwich-type anion complexes that are observed when the two cyclopeptide moieties are not covalently connected and to obtain a 1:1 stoichiometry for these aggregates. Electrospray ionization mass spectrometry and NMR spectroscopic investigations showed that the bridged bis(cyclopeptide) does indeed form defined 1:1 complexes with halides, sulfate, and nitrate. ROESY NMR spectroscopy and molecular modeling allowed a structural assignment of the sulfate complex in solution. The stabilities of various anion complexes were determined by means of NMR titrations and isothermal titration microcalorimetry in 50% water/methanol. Both methods gave essentially the same quantitative results, namely stability constants that varied in the range 105-102 M-1 and decreased in the order SO42- > I- > Br- > Cl- > NO3-. This order was rationalized in terms of the size of the anions with the larger anions forming the more stable complexes because they better fit into the cavity of the host. The ability of sulfate to form stronger hydrogen bonds to the NH groups of the receptor, in addition to its slightly larger ionic radius with respect to iodide, causes the higher stability of the sulfate complex. No significant effect of the countercation on complex stability was observed. Furthermore, complex stability is enthalpically as well as entropically favored. A comparison of the iodide and sulfate complex stabilities of the ditopic receptor with those of a cyclopeptide that forms 1:1 anion complexes in solution showed that the presence of a second binding site increases complex stability by a factor of 100-350.
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Kubik S, Goddard R. Conformation and anion binding properties of cyclic hexapeptides containing L-4-hydroxyproline and 6-aminopicolinic acid subunits. Proc Natl Acad Sci U S A 2002; 99:5127-32. [PMID: 11943849 PMCID: PMC122733 DOI: 10.1073/pnas.062625299] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two cyclic hexapeptides containing alternating all R and all S configured Ll-(4R/S)-hydroxyproline and 6-aminopicolinic acid subunits are presented, and the influence of the hydroxyl groups on the solubility, conformation, and receptor properties is investigated. Cyclopeptide 2, containing the natural 4R configured hydroxyproline, adopts a conformation similar to that of the unsubstituted peptide 1, which is able to bind anions such as halides and sulfate in aqueous solution. 2 also interacts with these anions, but whereas 1 forms sandwich type 2:1 complexes, in which the anion is bound by two cyclopeptide moieties, 2 forms 1:1 complexes. The stabilities of the halide and sulfate complexes of 2 range between 10(0) and 10(2) M(-1) in 80% D(2)O/CD(3)OD. Complex formation is detectable even in water, but with slightly smaller stability constants. Using this information a quantitative evaluation of the stability of the 2:1 complexes of 1, for which overall stability constants in the order 10(4) to 10(5) M(-2) in 80% D(2)O/CD(3)OD were observed, was made. In contrast to 2, the conformation of 3, containing the non-natural 4S configured hydroxyproline, is strongly affected by the presence of the hydroxyl groups. In d(6)-DMSO and methanol/water mixtures a slow conformational equilibrium between two C(3)-symmetrical conformers is observed, and 3 is thus much less preorganized for anion binding than either 1 or 2.
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Kubik S, Bitta J, Goddard R, Kubik D, Pohl S. Receptor properties of cyclic peptides composed of alternating natural amino acids and 3-aminobenzoic acid derivatives. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2001. [DOI: 10.1016/s0928-4931(01)00380-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Pohl S, Goddard R, Kubik S. A new cyclic tetrapeptide composed of alternating l -proline and 3-aminobenzoic acid subunits. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)01505-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Bitta J, Kubik S. Cyclic hexapeptides with free carboxylate groups as new receptors for monosaccharides. Org Lett 2001; 3:2637-40. [PMID: 11506597 DOI: 10.1021/ol016158l] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[structure: see text]. Cyclic hexapeptides composed of alternating L-proline and 3-aminobenzoic acid subunits with substituents on the aromatic subunits that contain free carboxylate groups are able to bind monosaccharides in 4% CD3OD/CDCl3. The binding selectivity of these peptides depends on the structure of the substituents on the aromatic subunits.
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Kubik S, Goddard R, Kirchner R, Nolting D, Seidel J. A Cyclic Hexapeptide Containing L-Proline and 6-Aminopicolinic Acid Subunits Binds Anions in Water This work was sponsored by the Deutsche Forschungsgemeinschaft. S.K. thanks D. Kubik for her committed help with the synthetic work and Prof. G. Wulff for his support. Angew Chem Int Ed Engl 2001; 40:2648-2651. [PMID: 11458360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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Kubik S, Goddard R, Kirchner R, Nolting D, Seidel J. Ein ausL-Prolin und 6-Aminopicolinsäure aufgebautes cyclisches Hexapeptid bindet Anionen in Wasser. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20010716)113:14<2722::aid-ange2722>3.0.co;2-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kubik S, Goddard R, Kirchner R, Nolting D, Seidel J. A Cyclic Hexapeptide Containing L-Proline and 6-Aminopicolinic Acid Subunits Binds Anions in Water. ANGEWANDTE CHEMIE (INTERNATIONAL ED. IN ENGLISH) 2001; 40:2648-2651. [PMID: 29712318 DOI: 10.1002/1521-3773(20010716)40:14<2648::aid-anie2648>3.0.co;2-#] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/31/2001] [Revised: 04/23/2001] [Indexed: 11/05/2022]
Abstract
A neutral receptor that binds anions by hydrogen bonds even in water is the cyclopeptide reported in this article. This property results from the particular structure of the complex in which the anions are effectively shielded from the surrounding solvent, as can be seen in the iodide complex shown.
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Kubik S, Goddard R. Fine Tuning of the Cation Affinity of Artificial Receptors Based on Cyclic Peptides by Intramolecular Conformational Control. European J Org Chem 2001. [DOI: 10.1002/1099-0690(200101)2001:2<311::aid-ejoc311>3.0.co;2-m] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Zinyuk L, Kubik S, Kaminsky Y, Fenton AA, Bures J. Understanding hippocampal activity by using purposeful behavior: Place navigation induces place cell discharge in both task-relevant and task-irrelevant spatial reference frames. Proc Natl Acad Sci U S A 2000; 97:3771-6. [PMID: 10716713 PMCID: PMC16315 DOI: 10.1073/pnas.97.7.3771] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Continuous rotation of an arena in a cue-rich room dissociates the stationary room-bound information from the rotating arena-bound information. This disrupted spatial discharge in the majority of place cells from rats trained to collect randomly scattered food. In contrast, most place cell firing patterns recorded from rats trained to solve a navigation task on the rotating arena were preserved during the rotation. Spatial discharge was preserved in both the task-relevant stationary and the task-irrelevant rotating reference frames, but firing was more organized in the task-relevant frame. It is concluded that, (i) the effects of environmental manipulations can be understood with confidence only when the rat's purposeful behavior is used to formulate interpretations of the data, and (ii) hippocampal place cell activity is organized in multiple overlapping spatial reference frames.
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Kubik S, Goddard R. Intramolecular conformational control in a cyclic peptide composed of alternating l-proline and substituted 3-aminobenzoic acid subunits. Chem Commun (Camb) 2000. [DOI: 10.1039/b000568l] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kubik S, Goddard R. A New Cyclic Pseudopeptide Composed of (l)-Proline and 3-Aminobenzoic Acid Subunits as a Ditopic Receptor for the Simultaneous Complexation of Cations and Anions. J Org Chem 1999. [DOI: 10.1021/jo991087d] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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91
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Kubik S. Large Increase in Cation Binding Affinity of Artificial Cyclopeptide Receptors by an Allosteric Effect. J Am Chem Soc 1999. [DOI: 10.1021/ja983970j] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kubik S, Wulff G. Book Review: Dictionary of Renewable Resources. Edited by H. Zoebelein. Angew Chem Int Ed Engl 1997. [DOI: 10.1002/anie.199719092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Zenker W, Kubik S. Brain cooling in humans--anatomical considerations. ANATOMY AND EMBRYOLOGY 1996; 193:1-13. [PMID: 8838492 DOI: 10.1007/bf00186829] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Vascular arrangements allowing a bulky transfer of venous blood from the skin of the head and from nasal and paranasal mucous membranes to the dura matter provide an excellent anatomical basis for the convection process of cooling, caused by evaporation of sweat or mucus. The dura mater, with its extraordinarily high vascularization controlled by a potent vasomotor apparatus, may transmit temperature changes to the cerebrospinal fluid (CSF) compartment. Temperature gradients of the CSF may in turn influence the temperature of brain parenchyma (1) directly, along the extensive contact area between the cerebrocortical surface and the CSF-compartment, or (2) indirectly, via brain arteries that extend over long distances and arborize within the subarachnoid space before entering the pial vascular network and brain parenchyma. Numerous subarachnoid and pial arterial branches exposed to the CSF have diameters in the range of the vessels of the retia mirabilia of animals in which selective brain cooling has been clearly established experimentally. It is also shown that the arrangements of venous plexuses within the vertebral canal provide anatomical preconditions for a cooling of the spinal cord via the CSF. The possibility of spinal cord and spinal ganglia cooling by temperature convection via venous blood--cooled in the venous networks of the skin of the back--flowing through numerous anastomoses to the external and internal vertebral plexuses and, finally, into the vascular bed of the spinal dura is discussed on the basis of anatomical facts.
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Azumaya I, Aebi R, Kubik S, Rebek J. Synthesis and coupling reactions of alpha,alpha-dialkylated amino acids with nucleobase side chains. Proc Natl Acad Sci U S A 1995; 92:12013-6. [PMID: 8618834 PMCID: PMC40286 DOI: 10.1073/pnas.92.26.12013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Several di- and tripeptides containing protected purine (adenine) and pyrimidine (thymine) residues on their side chains were synthesized. The parent amino acids alpha, alpha-dialkylated in a symmetrical manner. An effective coupling procedure was developed for these sterically hindered amino acids: the fluoren-9-ylmethyloxycarbonyl-protected amino acid was dehydrated to its oxazolinone form, which was coupled in good yields with amino esters in hot tetrachloroethane.
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Kubik S. [Topography of the hypophysis and its neighboring structures]. PRAXIS 1995; 84:750-769. [PMID: 7597363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The first part of the article informs about four points: the skeletal structures of the middle cranial fossa, the basic divisions of the gland and their connections with the hypothalamus, its blood supply, and its development. The topographic part deals with the incorporation of the pituitary gland in the sella turcica, its relationship to the meninges, the subarachnoid cavity and other neighbouring structures, especially the sphenoidal sinus, the posterior ethmoidal cells as well as the chiasma opticum. With respect to the latter, the position of the fibres in the optic nerve, chiasma and optic tract and the consequences of lesions in characteristic areas are described. Finally, the variant structures of the cavernous sinus and the topography of its contents are discussed. Detailed data can be found about the course of the oculomotor nerves and the possible locations of their lesions.
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Naidich TP, Valavanis AG, Kubik S. Anatomic relationships along the low-middle convexity: Part I--Normal specimens and magnetic resonance imaging. Neurosurgery 1995; 36:517-32. [PMID: 7753352 DOI: 10.1227/00006123-199503000-00011] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Sagittal sections of anatomic specimens and magnetic resonance images well display the individual gyri and sulci along the low-middle convexity. Those familiar with the typical pattern and with the common normal variations will be able to use sagittal magnetic resonance imaging to correctly localize lesions by identifying: (a) the five major rami of the sylvian fissure; (b) the subdivision of the triangular inferior frontal gyrus into the M-shaped partes orbitalis, triangularis, and opercularis by the anterior horizontal and anterior ascending rami of the sylvian fissure; (c) the zig-zag shape of the middle frontal gyrus, which characteristically angles sharply and inferiorly to fuse with the anterior surface of the precentral gyrus; (d) T-shaped bifurcation of the posterior end of the inferior frontal sulcus to form the inferior precentral sulcus; (e) separation of the central sulcus from the sylvian fissure by union of the opercular ends of the precentral and postcentral gyri to form the subcentral gyrus inferior to the central sulcus; (f) narrower sagittal dimension of the postcentral gyrus than the precentral gyrus; (g) horseshoe shape of the supramarginal gyrus perched atop the posterior ascending ramus of the sylvian fissure; (h) similar horseshoe shape of the angular gyrus perched atop the posterior end of the superior temporal sulcus; (i) commonly intercalated accessory presupramarginal and preangular gyri; and (j) the arcuate course of the intraparietal sulcus, which separates the superior from the inferior parietal lobules. The anatomic relationships described are more nearly constant anteriorly than posteriorly. When used as described, they prove helpful in correctly localizing pathology and in planning a surgical approach to lesions that may be difficult to localize on the basis of axial or coronal plane magnetic resonance images.
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Kubik S, Manestar M. Topographic relationship of the ventromedial lymphatic bundle and the superficial inguinal nodes to the subcutaneous veins. Clin Anat 1995; 8:25-8. [PMID: 7535176 DOI: 10.1002/ca.980080104] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The relationships between lymph vessels and veins are of clinical importance for the prevention of injury to collectors and resulting edema after removal of veins. Injection preparations of the lymph vessels and veins showed that on the dorsum of the foot the collectors overcross the veins; however, in all remaining areas they undercross them. Only the great saphenous vein is overcrossed by lymph collectors. It also has accompanying lymph vessels but its vascular sheath, however, does not contain any lymph vessels. The position of the collectors depends on the thickness of the subcutaneous adipose tissue. On the dorsum of the foot the lymphatics are often closely bound up with the corium; on the lower leg, however, they are embedded in the adipose tissue. Some collectors are closely related to perforator veins. In the knee region the lymph bundle ascends dorsomedially to the medial condylus of the femur. On the thigh, where the subcutaneous fatty tissue is thick, the collectors from three layers. The superficial inguinal lymph nodes draining the leg and the external genitalia are situated around the saphenous opening and are closely related to the subinguinal venous star, so that in surgical intervention the collectors of this region are more exposed to danger than in other regions.
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Kubik S, Meissner RS, Rebek J. Synthesis of α,α-dialkylated amino acids with adenine or thymine residues a new mild and facile hydrolysis of hydantoins. Tetrahedron Lett 1994. [DOI: 10.1016/s0040-4039(00)73454-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kubik S, Wulff G. Chemical synthesis and complexing behaviour of branched cyclodextrins composed of an amylose and a β-cyclodextrin residue. MACROMOL CHEM PHYS 1994. [DOI: 10.1002/macp.1994.021950522] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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