TY - JOUR ID - 1726 TI - Analysis of amino acids by HPLC/electrospray negative ion tandem mass spectrometry using 9-fluorenylmethoxycarbonyl chloride (Fmoc-Cl) derivatization JO - Amino Acids PY - 2014 SP - 2799-2808 AU - Ziegler, J. AU - Abel S. VL - 46 UR - http://link.springer.com/search?query=Ziegler%2C+J%C3%B6rg&search-within=Journal&facet-journal-id=726 DO - 10.1007/s00726-014-1837-5 AB - A new method for the determination of amino acids is presented. It combines established methods for the derivatization of primary and secondary amino groups with 9-fluorenylmethoxycarbonyl chloride (Fmoc-Cl) with the subsequent amino acid specific detection of the derivatives by LC–ESI–MS/MS using multiple reaction monitoring (MRM). The derivatization proceeds within 5 min, and the resulting amino acid derivatives can be rapidly purified from matrix by solid-phase extraction (SPE) on HR-X resin and separated by reversed-phase HPLC. The Fmoc derivatives yield several amino acid specific fragment ions which opened the possibility to select amino acid specific MRM transitions. The method was applied to all 20 proteinogenic amino acids, and the quantification was performedusing l-norvaline as standard. A limit of detection as low as 1 fmol/μl with a linear range of up to 125 pmol/μl could be obtained. Intraday and interday precisions were lower than10 % relative standard deviations for most of the amino acids. Quantification usingl-norvaline as internal standard gave very similar results compared to the quantificationusing deuterated amino acid as internal standards. Using this protocol, it was possible to record the amino acid profiles of only a single root from Arabidopsis thaliana seedlings and to compare it with the amino acid profiles of 20 dissected root meristems (200 μm). A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 353 TI - Heterologous expression and characterization of human glutaminyl cyclase: evidence for a disulfide bond with importance for catalytic activity JO - Biochemistry PY - 2002 SP - 10849-10857 AU - Schilling, S. AU - Hoffmann, T. AU - Rosche, F. AU - Manhart, S. AU - Wasternack, C. AU - Demuth, H.-U. VL - 41 UR - AB - A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 522 TI - Concentration of dilute protein solutions prior to sodium dodecylsulfate polyacrylamide gel electrophoresis JO - Anal. Biochem PY - 1997 SP - 257-260 AU - Ziegler, J. AU - Vogt, T. AU - Miersch, O. AU - Strack, D. VL - 250 UR - http://www.sciencedirect.com/science/article/pii/S000326979792248X DO - 10.1006/abio.1997.2248 AB - A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER -