| 61. |
- Okroj, Marcin, et al.
(författare)
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Structural basis and functional effects of the interaction between complement inhibitor C4b-binding protein and DNA.
- 2008
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Ingår i: Molecular Immunology. - : Elsevier BV. - 1872-9142 .- 0161-5890. ; 46, s. 62-69
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Tidskriftsartikel (refereegranskat)abstract
- Human C4b-binding protein (C4BP) is a soluble, multiple-subunit inhibitor of complement that circulates in blood. Recently C4BP was shown to bind DNA, reduce DNA release from necrotic cells and limit DNA-mediated complement activation in solution. Herein we employed nuclear magnetic resonance spectroscopy to measure chemical shift perturbations and used them to restrain the computational docking of a B-form 10-base-pair DNA molecule onto the solution structure of C4BP alpha-chain complement control protein (CCP) domains 1-2 (C4BP12). Six amino acid residues located on one face of the interdomain junction - Val(38), Ser(40), Thr(43), Tyr(62), Lys(63) and Arg(64) - exhibited the largest chemical shift changes. In the model, the DNA lies in a cleft formed by the interdomain interface. The double-helix is perpendicular to the long axis of C4BP12 consistent with the multiple arms of C4BP binding to adjacent sites on a longer DNA molecule. The DNA lies in a region previously shown to bind C4b and heparin and these molecules (but not C3b) inhibited the DNA-C4BP interaction. Nonetheless, crucial C4BP functions such as cofactor activity for factor I cleavage of C4b and C3b, and decay acceleration of the classical C3 convertase appeared not to be affected by the presence of DNA. Taken together these results reinforce the case for the occupation of some of the seven arms of C4BP in a multivalent interaction with DNA or surface bound glycosaminoglycans while other arms engage C4b or C3b.
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| 62. |
- Pacala, S, et al.
(författare)
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The North American carbon budget past and present
- 2007
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Ingår i: The First State of the Carbon Cycle Report (SOCCR), The North American Carbon Budget and Implications for the Global Carbon Cycle.
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Bokkapitel (populärvet., debatt m.m.)
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| 63. |
- Petersson, M. J., et al.
(författare)
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Unexpected regiospecific reactivity of a substituted phthalic anhydride
- 2007
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Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020 .- 1464-5416. ; 63:6, s. 1395-1401
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Tidskriftsartikel (refereegranskat)abstract
- Regioselective nucleophilic addition at C1 of anhydride 7 by a range of nucleophiles occurs to produce amide, ester and thioester derivatives 8-15 (60-99%). The increased electrophilic reactivity of the C I carbonyl group of anhydride 7 is supported by a competition experiment with phthalic anhydride. Unexpected formation of lactams 18 and 19 from amides 12 and 13 was shown to proceed via the lactamols 16 and 17 and could be controlled by the reaction conditions. The solid-state structure of 19 is reported. (c) 2006 Published by Elsevier Ltd.
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| 64. |
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| 65. |
- Valiente-Dobon, JJ, et al.
(författare)
-
High-spin rotational structures in Kr-76
- 2005
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 71:3
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Kr-76(36)40 have been populated in the Ca-40(Ca-40,4p)Kr-76 fusion-evaporation reaction at abeam energy of 165 MeV and studied using the Gammasphere and Microball multidetector arrays. The ground-state band and two signature-split negative parity bands of Kr-76 have been extended to similar to 30 (h) over bar. Lifetime measurements. using the Doppler-shift attenuation method show that the transition quadrupole moment of these three bands decrease as they approach their maximum-spin states. Two signatures of a new rotational structure with remarkably rigid rotational behavior have been identified. The high-spin properties of these rotational bands are analyzed within the framework of configuration-dependent cranked Nilsson-Strutinsky calculations.
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