Tau is a microtubule-associated phosphoprotein (MAP) localized in neuronal axons. That promotes tubulin polymerization and microtubules stabilization. Tau proteins constitute a family of six isoforms ranging from 352 to 441 amino acids. The tau variants differ from each other by the presence of either three or four repeated regions in the carboxyl terminal of the molecule and the absence or presence of one or two inserts in the portion ofamino-terminal. Tau is hyperphosphorylated by ERK, GSK-3, TPKII, and CDK5. At least thirty phosphorylation sites have been described including Thr39, Ser46, Thr50, Thr69, Thr153, Thr175, Thr181, Ser198, Ser199, Ser202, Thr205, Ser208, Ser210, Thr212, Ser214, Thr217, Thr231, Ser235, Ser237, Ser241, Ser262, Ser285, Ser305, Ser324, Ser352, Ser356, Ser396, Ser400, Thr403, Ser404, Ser409, Ser412, Ser413, Ser416, and Ser422. Specifically, TPKII phosphorylates serines 202 and 404. GSK-3β transfection phosphorylates serines 199, 202, 235, 396, 404, and 413, and threonines 205 and 231. These sites are among the major atypical phosphorylation sites of tau. Phosphorylation on these sites reduces the ability of a given tau species to promote microtubule self-assembly. Hyperphosphorylated tau is the major protein of the paired helical filaments (PHFs) which make up the pathological neurofibrillary tangles of Alzheimer’s disease (AD). PHFs are also found in the lesions of other central nervous system disorders. GenScript Rabbit Anti-Tau (Phospho-Ser409) Polyclonal Antibody is developed in rabbit using synthetic phospho-peptide (KLH-coupled) corresponding to residues surrounding phospho-serine 409 of human tau.
Affinity chromatography using phosphopeptide and cross-adsorbed with the corresponding non-phosphopeptide.
Reconstitute the lyophilized powder with deionized water (or equivalent) to an final concentration of 0.5 mg/ml.
GenScript Rabbit Anti-Tau (Phospho-Ser409) Polyclonal Antibody detects human tau only when phosphorylation occurs at serine 409. It has not yet been tested for other species.
GenScript Rabbit Anti-Tau (Phospho-Ser409) Polyclonal Antibody should be stored lyophilized until use. It remains stable in lyophilized form for at least two years if stored at 2-8°C. The reconstituted antibody can be stored for 2-3 weeks 2-8°C or for up to two years at -20°C or below. Avoid repeated freezing and thawing cycles.
Working concentrations for specific applications should be determined by the investigator. The appropriate concentrations may be affected by secondary antibody affinity, antigen concentration, detection method sensitivity, temperature, length of incubations, and many other factors. The suitability of this antibody for applications other than those listed below has not been determined. The following concentration ranges are starting recommendations for this product. ELISA: 0.05-0.2 µg/ml Western blot: 0.5-2 µg/ml Other Applications: user optimized.
Western blot analysis of phosphorylated recombinant human Tau protein, stimulated by GSK3β, using Rabbit Anti-Tau (Phospho-Ser409) Polyclonal Antibody (GenScript, A00899) Lane 1: Rabbit Anti-Tau (Phospho-Ser409) Polyclonal Antibody Lane 2: Rabbit Anti-Tau (Phospho-Ser409) Polyclonal Antibody pre-incubated with nonphoshpo-peptide Lane 3: Rabbit Anti-Tau (Phospho-Ser409) Polyclonal Antibody pre-incubated with phoshpo-peptide Secondary Antibody: Goat Anti-Rabbit IgG (H&L) [HRP] (GenScript, A00098) The signal was developed with LumiSensorTM HRP Substrate Kit (GenScript, L00221V500)