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C Pendley

Publications and source records attributed to C Pendley.

3 recordsLinked to original sources
PubMed2005

A one-step, competitive electrochemiluminescence-based immunoassay method for the quantification of a fully human anti-TNFalpha antibody in human serum.

A quantitative, one-step, competitive electrochemiluminescence (ECL)-based immunoassay for the determination of a fully human, anti-TNFalpha monoclonal antibody in human serum has been developed. A biotinylated, mouse anti-variable region-specific antibody and a ruthenium-labeled anti-TNFalpha antibody were the only specific reagents needed to develop the assay. A single incubation step of 2 h followed by ECL detection was used. The assay was capable of measuring the analyte in neat serum over approximately a 1600-fold range with higher concentrations measured following a single dilution. Assay accuracy, precision, and reproducibility were suitable to support pharmacokinetic studies of the analyte. This competitive assay format offers an alternative approach to the development of immunoassays for the measurement of macromolecules in complex matrices to support preclinical and clinical studies.

Animals↗
PubMed1990

2,3-Diphosphoglycerate phosphatase/synthase: a potential target for elevating the diphosphoglycerate level in human red blood cells.

To exploit the well documented effect of 2,3-diphosphoglyceric acid (2,3-DPG) in enhancing oxygen delivery by human erythrocytes, we have investigated whether the DPG synthase/phosphatase enzyme system can be targeted to increase DPG levels in the cell. The hydrolytic activity (phosphatase) of the DPG metabolizing enzyme complex exhibits a marked dependence on a physiological effector, 2-phosphoglycolate. Little phosphatase activity is detected in the absence of this activator irrespective of the concentrations of the substrate. The phosphoglycolate-dependent phosphatase activity is competitively inhibited by a glycolytic intermediate, 3-phosphoglyceric acid (3-PGA). The 3-PGA inhibition persists when the 2,3-DPG concentration is raised to saturation level. In contrast, 3-PGA enhances the DPG synthase activity in a dose-dependent manner. In intact red cells, one-half of the cellular DPG content is depleted after 6 hr at 37 degrees C in glucose-free medium. The rate of 2,3-DPG degradation is accelerated when the cellular level of phosphoglycolate is increased by incubation with exogenous glycolate. Together, these results indicate that 2,3-DPG content in erythrocytes can be directly regulated through modulation of phosphatase/synthase activities. In support of this notion, a pyruvate kinase inhibitor, L-alanine, increases by 2-fold the cellular 3-PGA level. This is accompanied by a significant increase (30%) in 2,3-DPG content in human red blood cells. It is postulated that the DPG-promoting action of 3-PGA is mediated through simultaneous phosphatase inhibition and synthase activation. Furthermore, as a result of increased DPG accumulation, the oxygen-hemoglobin dissociation curve in L-alanine-treated cells is rightward shifted by 2.5 torr.

2,3-Diphosphoglycerate↗