Synonyms
Persephin, PSP, PSPN
Description
Persephin is a secreted protein belonging to the glial cell line-derived neurotrophic factor (GDNF) family of the TGF-beta superfamily. It shares 38 - 46% amino acid (aa) identity with family members GDNF, neurturin and artemin. Persephin is expressed at very low levels in most tissues. The 156 aa, 10 - 12 kDa mature protein contains a signal sequence, a pro-domain and a 96 aa mature sequence with several cysteines that are conserved among family members. It circulates as an unglycosylated disulfide-linked homodimer. Mature human Persephin shares 81% and 80%, 89% and 87% amino acid sequence identity with mouse, rat, bovine and canine Persephin, respectively. Like other GDNF family members, Persephin acts through engagement of GRF alpha 4, a glycosylphosphatidylinositol (GPI)-linked GDNF receptor family (GRF) member that signals through the receptor tyrosine kinase RET. Persephin is reported to promote both the survival and growth of central dopaminergic and motor neurons, and kidney development. These effects are correlated with the expression patterns of GFR alpha 4, and RET. Functional GFR alpha 4 isoforms are found only in thyroid, adrenal medulla and portions of the central nervous system, and include GPI-linked, transmembrane and soluble forms. In vitro, Persephin promotes survival only in neurons which coexpress GPI-linked GFR alpha 4 with RET. This effect does not show a strong correlation to the recruitment of RET in lipid rafts seen with other GDNF family members.
Molecular Weight
Approximately 20.7 kDa.
AA sequence
ALAGSCRLWS LTLPVAELGL GYASEEKVIF RYCAGSCPQE ARTQHSLVLA RLRGRGRAHG RPCCQPTSYA DVTFLDDQHH WQQLPQLSAA ACGCGG
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Purity
>95% by SDS-PAGE and HPLC analyses.
Biological Activity
The ED50 as determined by a cell proliferation assay using human TT medullary thyroid cancer cells is less than 0.1 ng/mL, corresponding to a specific activity of > 1.0 × 107 IU/mg. Fully biologically active when compared to standard.
Endotoxin
< 0.1 EU per 1μg of the protein by the LAL method.
Formulation
Lyophilized from a 0.2 μm filtered concentrated solution in 30% ACN, 0.1% TFA, 150 mM NaCl.
Reconstitution
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1% BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20℃. Further dilutions should be made in appropriate buffered solutions.