Human AA(Arachidonic Acid) ELISA Kit

Herein, a novel molecularly imprinted polymer (MIP) modified spatial-resolved "on-off" ratiometric electro-chemiluminescence (ECL) sensing platform based on a closed bipolar electrode (BPE) has been reported for highly accurate and selective detection of ascorbic acid (AA). AA-imprinted MIP was decorated on the anode of the BPE, and Ru (bpy)(3)(2+) in the anode electrolyte served as anode-emitter, while ZnIn2S4 as the other ECL emitter was coated on the cathode. Rebinding of AA at anode promoted ECL response of ZnIn2S4 (440 nm) at cathode. Meanwhile, the ECL response at 605 nm decreased, arising from the hindered reaction of Ru (bpy)(3)(2+) on the anode surface. Therefore, an "on-off" BPE-ECL sensing platform was fabricated and showed distinguished performance in repeatability and selectivity thanks to the ratio correction effect and the specific recognition from MIP. The linear range for AA detection is from 50 nM to 3 mu M with a low detection limit of 20 nM (S/N = 3). The assay deviation of the ratio responses largely declined by about 15 and 5 times compared with the ones from single pole in the aspect of repeatability and long-term stability, respectively. This work provides a reliable and stable sensing pattern for practical application, which also furnishes a strategy for designing simple and low-cost ECL sensing devices.

BackgroundPost-translational modifications (PTM) of amino acid (AA) side chains in peptides control protein structure and functionality. PTMs depend on the specific AA characteristics. The reactivity of cysteine thiol-based PTMs are unique among all proteinaceous AA. This pipeline aims to ease the identification of conserved AA of polypeptides or protein families based on the phylogenetic occurrence in the plant kingdom. The tool is customizable to include any species. The degree of AA conservation is taken as indicator for structural and functional significance, especially for PTM-based regulation. Further, this pipeline tool gives insight into the evolution of these potentially regulatory important peptides.ResultsThe web-based or stand-alone pipeline tool Conserved Cysteine Finder (ConCysFind) was developed to identify conserved AA such as cysteine, tryptophan, serine, threonine, tyrosin and methionine. ConCysFind evaluates multiple alignments considering the proteome of 21 plant species. This exemplar study focused on Cys as evolutionarily conserved target for multiple redox PTM. Phylogenetic trees and tables with the compressed results of the scoring algorithm are generated for each Cys in the query polypeptide. Analysis of 33 translation elongation and release factors alongside of known redox proteins from Arabidopsis thaliana for conserved Cys residues confirmed the suitability of the tool for identifying conserved and functional PTM sites. Exemplarily, the redox sensitivity of cysteines in the eukaryotic release factor 1-1 (eRF1-1) was experimentally validated.ConclusionConCysFind is a valuable tool for prediction of new potential protein PTM targets in a broad spectrum of species, based on conserved AA throughout the plant kingdom. The identified targets were successfully verified through protein biochemical assays. The pipeline is universally applicable to other phylogenetic branches by customization of the database.