Human SIRP alpha/CD172a Protein

产品信息(Product Info)

Recombinant Human SIRP alpha/CD172a Protein is expressed from Expi293 with His tag at the C-terminal. It contains Glu31-Arg370.[Accession | P78324-1]

分子量大小(Molecular Weight)

The protein has a predicted MW of 38.1 kDa. Due to glycosylation, the protein migrates to 45-65 kDa based on Tris-Bis PAGE result.


Less than 1EU per μg by the LAL method.


> 95% as determined by Tris-Bis PAGE
> 95% as determined by HPLC


Lyophilized from 0.22μm filtered solution in PBS (pH 7.4). Normally 5% trehalose is added as protectant before lyophilization.


Centrifuge tubes before opening. Reconstituting to a concentration more than 100 μg/ml is recommended (usually we use 1mg/ml solution for lyophilization). Dissolve the lyophilized protein in distilled water.


-20 to -80°C for 12 months as supplied from date of receipt.
-20 to -80°C for 3-6 months in unopened state after reconstitution.
2-8°C for 2-7 days after reconstitution.
Recommend to aliquot the protein into smaller quantities for optimal storage. Please avoid freeze-thaw cycles.

产品数据(Assay Data)
Tris-Bis PAGE

Human SIRP alpha on Tris-Bis PAGE under reduced condition. The purity is greater than 95%.


The purity of Human SIRP alpha is greater than 95% as determined by SEC-HPLC.


Immobilized Human SIRP alpha, His Tag at 0.5μg/ml (100μl/Well) on the plate. Dose response curve for Human CD47, hFc Tag with the EC50 of 38.1ng/ml determined by ELISA.

Blocking Data

Serial dilutions of Anti-SIRP alpha Antibody were added into Human SIRP alpha, His Tag: Biotinylated Human CD47, His Tag binding reactions.The half maximal inhibitory concentration (IC50) is 73.46ng/ml.

SPR Data

Human SIRP alpha, His Tag captured on Protein A Chip via Anti-His Antibody can bind Human CD47, hFc Tag with an affinity constant of 20.6nM as determined in SPR assay (Biacore T200).

SPR Data

Anti-SIRP alpha Antibody captured on CM5 Chip via Protein A can bind Human Sirpa, His Tag with an affinity constant of 2.81 nM as determined in SPR assay (Biacore T200).


Signal regulatory protein α (SIRPα) is a regulatory membrane glycoprotein from SIRP family expressed mainly by myeloid cells and also by stem cells or neurons.SIRPα acts as inhibitory receptor and interacts with a broadly expressed transmembrane protein CD47 also called the "don´t eat me" signal.Cancer cells highly expressed CD47 that activate SIRP α and inhibit macrophage-mediated destruction.


CD172a; BIT; MFR; MYD1; MYD-1; P84; PTPNS1; SHPS1; SHPS-1; SIRP alpha; SIRPA;


(1)Weiskopf K , Ring A M , Ho C C M , et al. Engineered SIRP? Variants as Immunotherapeutic Adjuvants to Anticancer Antibodies[J]. Science, 2013, 341(6141):88-91.