Human Thrombopoietin / TPO Protein, premium grade

分子別名（Synonym）

THPO,MGC163194,MGDF,MKCSF,ML,MPLLG,TPO,THCYT1

表達(dá)區(qū)間及表達(dá)系統(tǒng)（Source）

Human Thrombopoietin Protein, premium grade (THN-H5216) is expressed from human 293 cells (HEK293). It contains AA Ser 22 - Gly 353 (Accession # P40225-1).

Predicted N-terminus: Ser 22

它是在我們嚴(yán)格的質(zhì)量控制體系下生產(chǎn)的，該體系包含一套全面的測試，包括無菌和內(nèi)毒素測試。在早期臨床前階段，產(chǎn)品性能經(jīng)過仔細(xì)驗(yàn)證和測試，以確保其與細(xì)胞培養(yǎng)用途或任何其他應(yīng)用的兼容性。

GMP-THNH25是THN-H5216的GMP版本。這兩種蛋白質(zhì)顯示出無法區(qū)分的性能特征，從而確保最終用戶從早期臨床前階段無縫過渡到后期臨床階段。

蛋白結(jié)構(gòu)（Molecular Characterization）

This protein carries no "tag".

The protein has a calculated MW of 35.5 kDa. The protein migrates as 75 kDa±5 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under reducing (R) condition (SDS-PAGE) due to glycosylation.

內(nèi)毒素（Endotoxin）

Less than 0.01 EU per μg by the LAL method.

宿主蛋白殘留（Host Cell Protein）

<0.5 ng/μg of protein tested by ELISA.

宿主核酸殘留（Host Cell DNA）

<0.02 ng/μg of protein tested by qPCR.

無菌（Sterility）

Negative

支原體（Mycoplasma）

Negative.

純度（Purity）

>95% as determined by SDS-PAGE.

制劑（Formulation）

Lyophilized from 0.22 μm filtered solution in 20 mM NaAc-HAc, pH5.0 with trehalose as protectant.

Contact us for customized product form or formulation.

重構(gòu)方法（Reconstitution）

Please see Certificate of Analysis for specific instructions.

For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.

存儲（Storage）

For long term storage, the product should be stored at lyophilized state at -20°C or lower.

Please avoid repeated freeze-thaw cycles.

This product is stable after storage at:

-20°C to -70°C for 24 months in lyophilized state;

-70°C for 3 months under sterile conditions after reconstitution.

背景（Background）

Thrombopoietin (Tpo), is a key regulator of megakaryocytopoiesis and thrombopoiesis. It is principally produced in the liver and is bound and internalized by the receptor Tpo R/c-mpl. Defects in the Tpo-Tpo R signaling pathway are associated with a variety of platelet disorders (1-3). The 353 amino acid (aa) human Tpo precursor is cleaved to yield the 332 aa mature protein. Mature human Tpo shares approximately 70% aa sequence homology with mouse and rat Tpo. It is an 8085 kDa protein that consists of an Nterminal domain with homology to Erythropoietin (Epo) and a Cterminal domain that contains multiple Nlinked and O-linked glycosylation sites (4, 5). Tissue specific alternate splicing of human Tpo generates multiple isoforms with internal deletions, insertions, and/or Cterminal substitutions (6). Tpo promotes the differentiation, proliferation, and maturation of MK and their progenitors (4, 5, 7). Several other cytokines can promote these functions as well but only in cooperation with Tpo (8, 9). Notably, IL-3 independently induces MK development, although its effects are restricted to early in the MK lineage (8, 9). Tpo additionally promotes platelet production, aggregation, ECM adhesion, and activation (10-13). It is cleaved by platelet-derived thrombin following Arg191 within the Cterminal domain and subsequently at other sites upon extended digestion (14). Both full length Tpo and shorter forms circulate in the plasma, with the shorter, Nterminal EPO-like domain forms showing significantly increased specific activity (4, 5, 15). The Cterminal domain is not required for binding to Tpo R or inducing MK growth and differentiation (5). Aside from its hematopoietic effects, Tpo is expressed in the brain where it promotes the apoptosis of hypoxia-sensitized neurons and inhibits neuronal differentiation by blocking NGF induced signaling (16, 17).