@article {4489, title = {Analysis of gamma-carboxyglutamic acid content of protein, urine, and plasma by capillary electrophoresis and laser-induced fluorescence}, journal = {Analytical Chemistry}, volume = {71}, number = {8}, year = {1999}, note = {ISI Document Delivery No.: 186XUTimes Cited: 12Cited Reference Count: 32}, month = {Apr}, pages = {1633-1637}, type = {Article}, abstract = {When the properties of an analyte are known, the separation system can be designed to make the analyte of interest migrate at either a much faster ora much slower velocity compared to other molecules in the sample matrix. A simple and sensitive method to analyze the gamma-carboxyglutamic acid (Gla) content of protein, urine, and plasma was developed using capillary electrophoresis with laser-induced fluorescence detection (CE-IIF), The separation method is designed according to the specific properties of three amino acids of interest. The number of Gla residues from three vitamin K-dependent proteins were estimated by quantifying the amount of fluorescein thiocarbamyl derivative of Gla after alkaline hydrolysis and fluorescein isothiocyanate labeling. Human prothrombin, blood coagulation factor X, and bovine osteocalcin were calculated to have 10.0 +/- 0.7, 11.0 +/- 0.6, and 2.1 +/- 0.1 Gla residues. per mole of protein, respectively, which agreed well with amino acid sequencing data. The analysis of free Gla content in urine and plasma was also demonstrated by this method. It was demonstrated that submicrograms of protein can be characterized by CE-LIF.}, keywords = {bone, CLINICAL-SIGNIFICANCE, GLUTAMIC-ACID, MARKERS, PROTHROMBIN, SERUM, VITAMIN-K}, isbn = {0003-2700}, url = {://000079756900025}, author = {Britz-McKibbin, P. and Vo, H. C. and MacGillivray, R. T. A. and Chen, D. D. Y.} } @article {4689, title = {Undercarboxylation of recombinant prothrombin revealed by analysis of gamma-carboxyglutamic acid using capillary electrophoresis and laser-induced fluorescence}, journal = {Febs Letters}, volume = {445}, number = {2-3}, year = {1999}, note = {ISI Document Delivery No.: 175YCTimes Cited: 6Cited Reference Count: 37}, month = {Feb}, pages = {256-260}, type = {Article}, abstract = {The gamma-carboxyglutamic acid (Gla) content of several variants of human prothrombin has been measured by using capillary electrophoresis and laser-induced fluorescence (CE-LIF). Both plasma-derived prothrombin and recombinant prothrombin contain ten residues of Gla per molecule of protein. In contrast, a variant of human prothrombin (containing the second kringle domain of bovine prothrombin) was separated into two populations that differed in their Gla content. Direct measurement of the Gla content showed an association with the presence or absence of the calcium-dependent conformational change that is required for prothombinase function. Thus, the CE-LIF assay is useful in determining the carboxylation status of recombinant proteins. (C) 1999 Federation of European Biochemical Societies.}, keywords = {baby hamster kidney, calcium, capillary electrophoresis, cell, EXPRESSION, FACTOR-X, gamma carboxy glutamic acid, GLUTAMIC-ACID, HUMAN PROTEIN-C, LASER-INDUCED FLUORESCENCE, METAL, PHOSPHOLIPID-BINDING-PROPERTIES, PROTHROMBIN, PURIFICATION, recombinant protein, RESIDUES, VITAMIN-K}, isbn = {0014-5793}, url = {://000079122800007}, author = {Vo, H. C. and Britz-McKibbin, P. and Chen, D. D. Y. and MacGillivray, R. T. A.} }