Thu, 21 Aug 2008 09:51:42 BST CiteULike: lechristophe's biacore http://www.citeulike.org/user/lechristophe/tag/biacore CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/lechristophe/article/1689740 <i>Science, Vol. 317, No. 5845. (21 September 2007), pp. 1732-1736.</i><br /><br />Free-solution, label-free molecular interactions were investigated with back-scattering interferometry in a simple optical train composed of a helium-neon laser, a microfluidic channel, and a position sensor. Molecular binding interactions between proteins, ions and protein, and small molecules and protein, were determined with high dynamic range dissociation constants (Kd spanning six decades) and unmatched sensitivity (picomolar Kd's and detection limits of 10,000s of molecules). With this technique, equilibrium dissociation constants were quantified for protein A and immunoglobulin G, interleukin-2 with its monoclonal antibody, and calmodulin with calcium ion Ca2+, a small molecule inhibitor, the protein calcineurin, and the M13 peptide. The high sensitivity of back-scattering interferometry and small volumes of microfluidics allowed the entire calmodulin assay to be performed with 200 picomoles of solute. 10.1126/science.1146559 Free-Solution, Label-Free Molecular Interactions Studied by Back-Scattering Interferometry Darryl Bornhop Joey Latham Amanda Kussrow Dmitry Markov Richard Jones Henrik Sorensen doi:10.1126/science.1146559 Science, Vol. 317, No. 5845. (21 September 2007), pp. 1732-1736. 2007-09-24T15:10:41-00:00 2007 Science 317 5845 1732 1736 biacore technique http://www.citeulike.org/user/lechristophe/article/1604851 <i>Cell Biol Int (15 July 2007)</i><br /><br />It is known that erythroid and non-erythroid spectrins binding of vesicles and monolayers containing PE proved sensitive to inhibition by red blood cell ankyrin. We now show that the bacterially-expressed recombinant peptides representing betaII(brain)-spectrin's ankyrin-binding domain and its truncated mutants showed lipid-binding activity, although only those containing a full-length amino terminal fragment showed high to moderate affinity towards phospholipid mono- and bilayers and a substantial sensitivity of this binding to inhibition by ankyrin. These results are in accordance with our published data on betaI-spectrin's ankyrin-binding domain [Hryniewicz-Jankowska A, et al. Mapping of ankyrin-sensitive, PE/PC mono- and bilayer binding site in erythroid beta-spectrin. Biochem J 2004;382:677-85]. Moreover, we tested also the effect of transient transfection of living cells of several cell-lines with vectors coding for GFP-conjugates including betaII and also betaI full-length ankyrin-binding domain and their truncated fragments on the membrane skeleton organization. The transfection with constructs encoding full-length ankyrin-binding domain of betaII and betaI spectrin resulted in increased aggregation of membrane skeleton and its punctate appearance in contrast to near normal appearance of membrane skeleton of cells transiently transfected with GFP control or construct encoding ankyrin-binding domain truncated at their N-terminal region. Our results therefore indicate the importance of N-terminal region for lipid-binding activity of the beta-spectrin ankyrin-binding domain and its substantial role in maintaining the spectrin-based skeleton distribution. Lipid-binding role of betaII-spectrin ankyrin-binding domain. Ewa Bok Ewa Plażuk Anita Hryniewicz-Jankowska Anna Chorzalska Agnieszka Szmaj Patrycja M Dubielecka Katarzyna Stebelska Witold Diakowski Marek Lisowski Marek Langner Aleksander F Sikorski doi:10.1016/j.cellbi.2007.06.014 Cell Biol Int (15 July 2007) 2007-08-29T13:56:37-00:00 2007 Cell Biol Int 1065-6995 ankyrin biacore lipids spectrin