Evaluation of a Chemiluminescent Enzyme Immunoassay for the Detection of Prostaglandin E-Major Urinary Metabolite (PGE-MUM).

Background: We developed a fully automated quantitative immunoassay for the detection of prostaglandin E-major urinary metabolite (PGE-MUM). In this study, we evaluated the analytical performance of this assay.

Methods: Sensitivity, within-run reproducibility, correlation with radioimmunoassay (RIA), cross-reactivity, dilution linearity, spike recovery performance, analyte stability, and effects of coexisting substances were evaluated.

Conformational changes during apoplastocyanin folding observed by photocleavable modification and transient grating.

A new method to investigate the initial protein folding dynamics is developed based on a pulsed laser light triggering method and a unique transient grating method. The side chain of the cysteine residue of apoplastocyanin (apoPC) was site-specifically modified with a 4,5-dimethoxy-2-nitrobenzyl derivative, where the CD and 2D NMR spectra showed that the modified apoPC was unfolded. The substituent was cleaved with a rate of about 400 ns by photoirradiation, which was monitored by the disappearance of the absorption band at 355 nm and the increase in the transient grating signal.