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Resultados filtrados por Publicador: The National Academy of Sciences

‣ Fluorescence-intensity distribution analysis and its application in biomolecular detection technology

Kask, Peet; Palo, Kaupo; Ullmann, Dirk; Gall, Karsten
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 23/11/1999 Português
Relevância na Pesquisa
451.2488%
A methodology, fluorescence-intensity distribution analysis, has been developed for confocal microscopy studies in which the fluorescence intensity of a sample with a heterogeneous brightness profile is monitored. An adjustable formula, modeling the spatial brightness distribution, and the technique of generating functions for calculation of theoretical photon count number distributions serve as the two cornerstones of the methodology. The method permits the simultaneous determination of concentrations and specific brightness values of a number of individual fluorescent species in solution. Accordingly, we present an extremely sensitive tool to monitor the interaction of fluorescently labeled molecules or other microparticles with their respective biological counterparts that should find a wide application in life sciences, medicine, and drug discovery. Its potential is demonstrated by studying the hybridization of 5′-(6-carboxytetramethylrhodamine)-labeled and nonlabeled complementary oligonucleotides and the subsequent cleavage of the DNA hybrids by restriction enzymes.

‣ Sequencing of 3-O sulfate containing heparin decasaccharides with a partial antithrombin III binding site

Shriver, Zachary; Raman, Rahul; Venkataraman, Ganesh; Drummond, Katherine; Turnbull, Jeremy; Toida, Toshihiko; Linhardt, Robert; Biemann, Klaus; Sasisekharan, Ram
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 12/09/2000 Português
Relevância na Pesquisa
453.33094%
Heparin- and heparan sulfate-like glycosaminoglycans (HLGAGs) represent an important class of molecules that interact with and modulate the activity of growth factors, enzymes, and morphogens. Of the many biological functions for this class of molecules, one of its most important functions is its interaction with antithrombin III (AT-III). AT-III binding to a specific heparin pentasaccharide sequence, containing an unusual 3-O sulfate on a N-sulfated, 6-O sulfated glucosamine, increases 1,000-fold AT-III's ability to inhibit specific proteases in the coagulation cascade. In this manner, HLGAGs play an important biological and pharmacological role in the modulation of blood clotting. Recently, a sequencing methodology was developed to further structure-function relationships of this important class of molecules. This methodology combines a property-encoded nomenclature scheme to handle the large information content (properties) of HLGAGs, with matrix-assisted laser desorption ionization MS and enzymatic and chemical degradation as experimental constraints to rapidly sequence picomole quantities of HLGAG oligosaccharides. Using the above property-encoded nomenclature-matrix-assisted laser desorption ionization approach, we found that the sequence of the decasaccharide used in this study is ΔU2SHNS...