Thrombopoietin (TPO) is a glycoprotein hormone produced mainly by the liver and the kidney which regulates the production of platelets by the bone marrow. TPO stimulates the production as well as differentiation of megakaryocytes, the bone marrow cells which fragment into large numbers of platelets.
Expression System
Escherichia coli
Sequence
SPAPPACDLRVLSKLLRDSHVLHSRLSQCPEVHPLPTPVLLPAVDFSLGEWKTQMEETKAQDILGAVTLLLEGVMAARGQLGPTCLSSLLGQLSGQVRLLLGALQSLLGTQLPPQGRTTAHKDPNAIFLSFQHLLRGKVRFLMLVGGSTLCVRRAPPTTAVPSRTSLVLTLNEL with polyhistidine tag at the N-terminus.
Species
Human
Tag
polyhistidine tag at the N-terminus
Endotoxin Level
<0.1 EU per 1 μg of the protein by the LAL method.
Activity
The ED50 for this effect is <2 ng/mL.
The specific activity of recombinant human TPO is > 5 x 105 IU/mg.
Purity
>95% as determined by SDS-PAGE. Ni-NTA chromatography
Formulation
The protein was lyophilized from a solution containing 1X PBS, pH 8.0.
Reconstitution
It is recommended to reconstitute the lyophilized protein in sterile H₂O to a concentration not less than 100 μg/mL and incubate the stock solution for at least 20 minutes to ensure sufficient re-dissolved.
SDS-PAGE analysis of recombinant human TPO