| Description | DescriptionAladdin provides purified Human Tyrosyl DNA Phosphodiesterase (Tdp1) purified to homogeneity to a single 68 kDa band on SDS-PAGE. Tdp1 is catalytically active and will remove a terminal 3’ phosphotyrosyl group from a specifically designed oligo target site (oligo-Tyr). Additionally,DescriptionAladdin provides purified Human Tyrosyl DNA Phosphodiesterase (Tdp1) purified to homogeneity to a single 68 kDa band on SDS-PAGE. Tdp1 is catalytically active and will remove a terminal 3’ phosphotyrosyl group from a specifically designed oligo target site (oligo-Tyr). Additionally, Aladdin scientists have demonstrated that Tdp1 will release topo I covalently attached to genomic DNA isolated from cells treated with camptothecin using Aladdin’s In Vivo Link Kit. Tdp1 is thought to be important in repair of topo/DNA adducts that form following topo-active drug therapy; therefore, there is considerable interest in identifying drugs that target Tdp1. Such drugs may work well in combination with topo targeting strategies.Figure 1. SDS-PAGE of Aladdin Purified Tdp1. The gel was intentionally overloaded with 20ug of protein to reveal minor breakdown products.Droduction infoUnit Defintion:One unit of Tdp1 can release the terminal Tyrosine from 20 ng of substrate (oligo-Tyr) in 30 min at 37° C.Tdp1 Reaction:Release of topo I from the covalent complex is shown below.Tdp1 Assays:Biochemical assays for Tdp1 can be carried out using an oligo nucleotide with a 3’ terminal tyrosine residue. Release of tyrosine from a 5’ 32P end labeled oligo is easily measured using a denaturing polyacrylamide gel or DNA sequencing gels. Shipping&storageThis product is shipped on wet ice and should be stored at – 20°C... Read More | Inquire | Unit Definition One unit will cause a change in A600 of 0.330 per minute at pH 5.7 at 37°C in a 2.0 ml reaction mixture (45 minute assay) | Inquire | Purity: >95%, by SDS-PAGE visualized with Coomassie® Blue Staining. Description： CD4, also known as L3T4, T4, and W3/25, is an approximately 55 kDa type I transmembrane glycoprotein that is expressed predominantly on thymocytes and a subset of mature T lymphocytes. It is a standard Purity: >95%, by SDS-PAGE visualized with Coomassie® Blue Staining. Description： CD4, also known as L3T4, T4, and W3/25, is an approximately 55 kDa type I transmembrane glycoprotein that is expressed predominantly on thymocytes and a subset of mature T lymphocytes. It is a standard phenotype marker for the identification of T cell populations. Mature human CD4 consists of a 371 amino acid (aa) extracellular region containing four immunoglobulin-like domains, a 22 aa transmembrane segment, and a 40 aa cytoplasmic domain. Within the ECD, human CD4 shares approximately 52% aa sequence identity with mouse and rat CD4. CD4 is expressed along with CD8 on double positive T cells during their development in the thymus. Either CD4 or CD8 expression is then lost, giving rise to single positive (SP) CD4+ or CD8+ mature T cells. CD4+ SP cells, also known as T helper cells, further differentiate into multiple subsets of CD4+ cells including Th1, Th2, Th17, Tfh, and Treg cells which regulate humoral and cellular immunity. CD4 is reexpressed on circulating CD8+ T cells upon activation and contributes to their cytotoxic effector activity. In human, CD4 is additionally expressed on macrophages, neutrophils, monocytes, NK cells, and neurons and glial cells in the brain. Similar CD4 distribution between species cannot be assumed as demonstrated by its presence on macrophages in human and rat but not in mouse. CD4 binds directly to MHC class II molecules on antigen presenting cells. This interaction contributes to the formation of the immunological synapse which is focused around the TCR-MHC class II-antigenic peptide interaction. Palmitoylation of two cysteine residues in the cytoplasmic tail of CD4 promotes the localization of CD4 in lipid rafts and its ability to augment TCR signaling via activation of the tyrosine kinase Lck. CD4 also functions as a chemotactic receptor for IL-16 and, in human, as a co-receptor for the gp120 surface glycoprotein of HIV-1... Read More |