The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform

Heli Sirén - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of monosaccharides and oligosaccharides in the pulp and paper industry by use of capillary zone electrophoresis: a review
    Analytical and bioanalytical chemistry, 2013
    Co-Authors: Salla Hiltunen, Heli Sirén
    Abstract:

    Carbohydrate Analysis is an important source of the information required for understanding and control of pulp and paper processes. The behavior of cellulose and hemicelluloses in the process, Carbohydrate–lignin interactions, and the enzymatic treatment of fibers are examples of situations for which reliable, fast, qualitative, and quantitative methods are required. New uses of lignocellulosic material have further increased the need for Carbohydrate Analysis. This review collates and summarizes the most important findings and approaches in the Analysis of wood-based Carbohydrates by use of capillary zone electrophoresis and provides an Analysis of the effect of different conditions on the separation, showing the advantages and limitations of the methods used. It provides guidelines for achieving higher quality and improved separation efficiency in Carbohydrate Analysis.

Elizabeth Higgins - One of the best experts on this subject based on the ideXlab platform.

  • Carbohydrate Analysis throughout the development of a protein therapeutic
    Glycoconjugate Journal, 2010
    Co-Authors: Elizabeth Higgins
    Abstract:

    This review discusses the challenges involved in the characterization of the glycosylation of therapeutic glycoproteins. The focus is on methods that are most commonly used in regulatory filings and lot release testing of therapeutic glycoproteins. The different types of assays for Carbohydrate Analysis are reviewed, including the distinction between assays appropriate for lot release or better suited to testing during early drug development or in-depth characterization of the glycosylation. Characteristics of the glycoprotein and production process that should be considered when determining the amount of testing, the number of different methods to employ and when the testing should be performed during development of protein therapeutics is also discussed.

Susumu Honda - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of Carbohydrates as 1-phenyl-3-methyl-5-pyrazolone derivatives by capillary/microchip electrophoresis and capillary electrochromatography.
    Journal of pharmaceutical and biomedical analysis, 2003
    Co-Authors: Susumu Honda, Shigeo Suzuki, Atsushi Taga
    Abstract:

    The 1-phenyl-3-methyl-5-pyrazolone (PMP) method has many advantages over hitherto reported methods based on reductive amination and hydrazone formation. This short review summarizes the various aspects of the PMP method, including the principle of derivatization, the simplicity of derivatization procedure, the high sensitivities to UV monitoring and ESI-MS, and the diversity of separation modes in capillary electrophoresis, and presents a number of application data for Carbohydrate Analysis in biological samples by this method. It also describes successful automation of Carbohydrate Analysis by in-capillary derivatization with PMP and miniaturization to microchip electrophoresis with whole channel UV detection allowing rapid (within 1 min) Analysis of small amounts of PMP derivatives of Carbohydrates. Furthermore, it discusses the possibility of capillary electrochromatography in Carbohydrate Analysis as PMP derivatives, and proposes an in-capillary modification strategy for improving column efficiency and elution time reproducibility.

  • Miniaturization in Carbohydrate Analysis.
    Electrophoresis, 2003
    Co-Authors: Shigeo Suzuki, Susumu Honda
    Abstract:

    Recent progress of microchip electrophoresis (ME) of Carbohydrates is overviewed. Carbohydrate Analysis by ME encounters difficulties such as lack of electric charge and deficiency of a chromophore/fluorophore in analyte molecules, however, it benefits from the accumulated knowledge of capillary electrophoresis (CE) and rapid separation of simple sugars also by ME, with high column efficiency comparable to CE, has become possible. Analysis at high pH, with electrochemical detection, is a promising approach because Carbohydrates can be ionized by weak dissociation of the hydroxyl groups and the in situ formed ionic species can be effectively separated by the zone electrophoresis mode. The separated species can be sensitively monitored by electrochemical detection on a gold or copper electrode. Ionization as borate complexes and refractometric detection is also possible, though sensitivity is lower. Introduction of UV-absorbing or fluorescent tags is potentially useful but the time-consuming derivatization processes sacrifice the rapidity of ME. Examples of ME of Carbohydrates as 1 -phenyl-3-methyl-5-pyrazolone (PMP; for simple mono- and oligosaccharides with UV detection), 8-amino-pyrene-1,3,6-trisulfonate (APTS; for oligosaccharides ladders with LIF detection), and 4-nitro-2,1,3-benzoxadiazole (NBD-F; for amino sugars and aminoalditols with LIF detection) derivatives are presented, with details of the analytical conditions. Since ME in a short separation channel enables rapid Analysis within 1 min, it presents an ideal tool for clinical Analysis, as shown in a few papers reporting protocols for specific blood glucose assay. Finally, the usefulness of microfluidic reactors and microarrays for enzyme-assisted Carbohydrate Analysis as well as glycan profiling is pointed out.

  • Carbohydrate Analysis and Carbohydrate-protein binding studies by capillary/microchip electrophoresis
    SEIBUTSU BUTSURI KAGAKU, 2002
    Co-Authors: Susumu Honda
    Abstract:

    Carbohydrates are widely distributed in nature and have multilateral functions. Recently glycobiology has evoked from the special interest in diverse functions of Carbohydrates covalently bound to proteins and lipids. It has been revealed that the Carbohydrate chains in such glycoconjugatges on cell surface are deeply associated with various cell events including division, differentiation, morphogenosis, fertilization, inflammation and metastasis. Although they are not formed by direct translation as in genomes and proteomes, they are important because many kinds of enzymes relating to their biosynthesis are under the control of genomes. Therefore, the Carbohydrates in glycoconjugates are attractive as postscriptomes, and the method development for Carbohydrate Analysis is an urgent theme in glycobiology. Since a number of structurally resembling species of carbohdrates coexist in biological samples, their Analysis requires the most efficient methods capable of high resolution and sensitive detection. For this reason capillary electrophoresis (CE) has become the most important tool for Carbohydrate Analysis. CE is, however, basically a method for ions, hence Carbohydrates, which are generally neutral, are not good objects of CE. In addition, Carbohydrates are normally difficult to sensitively detect, because they lack in chromophore/fluorophore. Chemical/enzymatic derivatization is the most appropriate strategy to solve these problems simultaneously. In this paper a number of methods for derivatization of Carbohydrates for CE are compared and criticized, and the 1-phenyl-3-methyl-5-pyrazolone (PMP) method and the methylglycamine-4-nitro-2, 1, 3-benzodiazole tagging method (MG-NBD method) are selected as the most suitable methods for routine and ultramicro analyses of Carbohydrates, respectively. A number of examples for their application are presented. A technique of automation of such Analysis by CE with in-capillary derivatization is also presented. Miniaturization of the PMP method to microchip electrophoresis (ME) has realized rapid Analysis of Carbohydrates in few ten seconds. The versatile functions of Carbohydrates stem from their binding with particular proteins, and therefore the study of Carbohydrate-protein binding is also important. CE can be performed in free solution, not necessitating addition of any supporting materials. Owing to this single-phase property of CE one can observe interaction occurring in a capillary as the migration time change of either of these reactants in running buffer containing the counterpart. By mathematical treatment of such migration time change, we could develop a series of methods for micro-ultramicro estimation of association constant. On the other hand we could succeed in finding out a number of proteins in biological samples, which can specifically bind to glycans and glycoconjugates.

Michael Snyder - One of the best experts on this subject based on the ideXlab platform.

  • Carbohydrate Analysis Prepares to Enter the “Omics” Era
    Chemistry & biology, 2002
    Co-Authors: Scott Bidlingmaier, Michael Snyder
    Abstract:

    In this issue, Houseman and Mrksich describe a Carbohydrate array preparation method that can be used to analyze protein-Carbohydrate interactions and to characterize the substrate specificity of a Carbohydrate-modifying enzyme. Carbohydrate chips were prepared by a novel procedure that allows the covalent attachment of Carbohydrate-diene conjugates to a specially engineered monolayer surface. The surface presents a precisely controllable ratio of reactive benzoquinone and inert ethylene glycol groups. Nonspecific adsorption of proteins to the surface is extremely low, and the surface is compatible with popular detection techniques. The immobilization technique was demonstrated to be compatible with recently developed automated solid phase Carbohydrate synthesis methods, paving the way for the development of highly complex Carbohydrate arrays.

Darrell N. Ward - One of the best experts on this subject based on the ideXlab platform.

  • Heterogeneity in porcine pituitary luteinizing hormone: amino acid and Carbohydrate Analysis.
    Endocrinology, 1992
    Co-Authors: S Van Dijk, Darrell N. Ward
    Abstract:

    Pituitary LH from porcine pituitary glands was purified by a buffered ethanol extraction procedure, ion exchange on DEAE- and carboxymethyl-cellulose, and molecular exclusion on Sephacryl S-200. Purity was assessed by amino acid composition, N-terminal sequence, and polyacrylamide gel electrophoresis. Subunits were isolated by countercurrent distribution and reverse phase HPLC. Four major forms of the alpha-subunit were detected: 1-96 (50%), 3-96 (23%), 4-96 (16%), and 7-96 (11%). [The original sequence report described only the 7-96 form, but we have detected the other forms in our studies of porcine FSH and in this and other species of LH.] Comparable N-terminal heterogeneity was not observed for the beta-subunit. Additional heterogeneity was observed for both subunits, attributable to heterogeneity in the N-linked oligosaccharide moieties. The isolated subunits were submitted to detailed compositional Carbohydrate Analysis, using pulsed amperometric detection of the HPLC-resolved sugar monomers after t...