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Ubiquitin Activating Enzymes
 | | | | The Proteasome Complex | Ubiquitin Enzymes | Antibodies for Proteasome Research | | | | The proteasome complex | | The proteasome is a 26S complex that contains a 20S proteasome, a multi-catalytic protease complex, and a 19S complex containing several ATPases and a binding site for ubiquitin chains. The proteolytic core of this complex, the 20S proteasome, contains multiple peptidase activities and functions as the catalytic machine. This core is composed of 28 subunits arranged in four heptameric, tightly stacked, rings (a7, b7, b7, a7) to form a cylindrical structure. The a-subunits (25.8 kDa) make up the two outer, and the b-subunits (22.3 kDa) the two inner rings of the stack. The entrance of substrate proteins to the active site of the complex is guarded by the a-subunits that only allow access for unfolded an d extended polypeptides. The proteolytic activity is confined to the b-subunits. Binding studies have shown 14 catalytic sites within the central chamber and involve a novel proteolytic mechanism in which the hydroxyl group of a threonine, located at the N-terminus of the b-subunit, acts as the nucleophilic group in the peptide hydrolysis. The specificity of the proteasome appears to be rather unspecific, however, the size of the hydrolysis products is always between 6 to 9 residues, which corresponds to the length between adjacent catalytic sites in the central chamber. | | | | Ubiquitin Enzymes | Ubiquitin-Activating Enzyme E1, Human (Cat. No. 662072)
The ubiquitin-activating enzyme, E1, is required for initiating a multi-step pathway for the covalent linkage of ubiquitin to target proteins. It catalyzes the first step in the ubiquitin-protein isopeptide bond formation and is a critical component for the initiation of conjugation reactions in vitro. Purity: ≥98% by SDS-PAGE.
| | | SUMO-Activating Enzyme E1 (Aos1/Uba2), Human (Cat. No. 662074)
SUMO (small ubiquitin-related modifier)-activating enzyme is a heterodimer composed of Uba2 and Aos1 polypeptides, which resembles ubiquitin in its structure, its ability to be ligated to other proteins, as well as in the mechanism of ligation. However, SUMOlation doesn't mark proteins for degradation. It mediates ATP-dependent activation of UBL1 (ubiquitin-like 1) and formation of a thiol-ester with a conserved cysteine residue on SAE2. Purity: ≥98% by SDS-PAGE.
| | | ISG15-Activating Enzyme E1, Human (Cat. No. 662076)
ISG15 (IFN-stimulated gene, 15kDa) proteins is a UbL (ubiquitin-like protein) that consist of two UB (ubiquitin)-related domains, N-terminal and C- terminal domains identical to UbLs conjugated to cellular proteins after IFNa/b stimulation. ISG15-activating enzyme is responsible for the first step in ISG15-protein isopeptide bond formation and is a critical component for the initiation of any in vitro conjugation reactions. Purity: ≥98% by SDS-PAGE.
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| | | | NEW! Antibodies for Proteasome Research | | Antibody | Description | mAb | pAb | Application(s) | Cat. No. | | Anti-Hip-2, Rabbit pAb | Polyclonal IgG, undiluted serum. Immunogen used was a synthetic peptide corresponding amino acid residues 1–12 of E2-25K/Hip-2. Detects the ~25 kDa E2-25K/Hip-2, an ubiquitin conjugating enzyme that plays a role in mediating amyloid-b neurotoxicity. Reacts with human, mouse, and rat. | | | FS, IB, IP, PS | | | | | | | | | Anti-20S Proteasome
a7-Subunit, Mouse mAb | Monoclonal IgG1, partially purified. Clone MCP72. S. Immunogen used was dinitrophenylated human placenta derived proteasomes. Detects ~ the 30 kDa 20S proteasome a7-subunit protein in human, rat, rabbit, and yeast. | | | IB, PS | | | | | | | | | | Anti-20S Proteasome Core Subunits, Rabbit pAb | Polyclonal IgG, undiluted serum. Immunogen used was human erythrocyte-derived proteasomes. Detects ~25-30 kDa 20S Proteasome core subunits (a5, a7, b1, b5i, and b7) in human, mouse, and yeast. | | | IB, IP, PS | | | | | | | | | Anti-20S Proteasome
b1-Subunit, Mouse mAb | Monoclonal IgG1, partially purified. Clone MCP421. Immunogen used was dinitrophenylated human placenta derived proteasomes. Detects ~ the 29 kDa 20S proteasome b1-subunit protein in human and rabbit. | | | IB | | | | | | | | | Anti-20S Proteasome
b3-Subunit, Mouse mAb | Monoclonal IgG1, partially purified. Clone MCP102. Immunogen used was dinitrophenylated proteasomes. Detects ~ 23 kDa 20S proteasome b3-subunit protein in human, mouse, rabbit, and rat. | | | IB | | | | | | | | | Anti-20S Proteasome
b4-Subunit, Rabbit pAb | Polyclonal IgG, partially purified. Immunogen used was a synthetic peptide corresponding to amino acids residues 72– 85 of human proteasome subunit b4 (Accession No. P49721) conjugated to KLH. Detects ~ 23 kDa 20S Proteasome b4-Subunit protein in human, mouse, and rat. | | | IB | | | | | | | | | Anti-20S Proteasome
b5i-Subunit, Rabbit pAb | Polyclonal IgG, partially purified. Immunogen used was recombinant protein corresponding to amino acids residues 23–223 of murine proteasome subunit b5i. Detects the ~26 kDa 20S proteasome subunit b5i, a subunit of the immunoproteasome in human, mouse, and rabbit. | | | IB, PS | | | | | | | | | | Anti-STAM1, Rabbit pAb | Polyclonal IgG, immunoaffinity-purified. Immunogen used was a synthetic peptide corresponding to the C-terminal region of STAM1. Detects the ~68 kDa STAM1 in human and mouse. STAM1 is a cytoplasmic adaptor protein that plays a major role in the sorting of ubiquitinated proteins. | | | IB, IP | | | | | | | | | | Anti-STAM2, Rabbit pAb | Polyclonal IgG, immunoaffinity-purified. Immunogen used was a synthetic peptide corresponding to the C-terminal of STAM2. Detects the ~58 kDa STAM2 in human and mouse. STAM2 plays a major role in the sorting of ubiquitinated proteins. | | | IB, IP | |
| | | Applications: FS: frozen sections; IB: immunoblotting; IP: immunoprecipitation; PS: paraffin sections
mAb: monoclonal antibody; pAb: polyclonal antibody | | | | | |
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