Qk007 recombinant human BMP2

Protein quality information for Qk007 batch #010

All our proteins are produced in-house by our scientists and we provide detailed quality data for each individual batch.  Please contact us any time by email support@qkine.com or phone +44 (0) 1223 491486 if you have any questions.

After aliquotting and lyophilising the protein, we choose a vial at random and reconstitute as recommended to ensure we are testing as close to the protein you will receive as possible.  Biochemical identity and purity of each batch is checked using SDS-PAGE, mass spectrometry and analytical reverse phase chromatography.  We use a sensitive test to ensure endotoxin levels are at industry leading low levels (<0.01 EU per µg protein). We also check that the correct amount of protein is recovered from the vial – it might sound basic but if you order 100 µg, we believe you should receive 100 µg.

Result: BMP2 migrates as a single band at 26 kDa in non-reducing (NR) and 13 kDa as a single monomeric species upon reduction (R).  No contaminating protein bands are visible.

Purified recombinant protein (7 µg) was resolved using 15% w/v SDS-PAGE in reduced (+β-mercaptothanol, R) and non-reduced conditions (NR) and stained with Coomassie Brilliant Blue R250.

Result: calculated molecular mass of the BMP2 dimer is 26058 Da. Result of the analysis: 26057.5 Da which is consistent with the calculated mass.  No significant heterogeneity is present.

MALDI mass spectrometric analysis is used to confirm the molecular mass of the intact protein and to reveal any heterogeneity that would not be evident in SDS-PAGE analysis. The results are compared with calculated mass of the protein with the assumption that all the cysteines are disulphide-linked. The different peaks represent different charge states of the protein.

Result: Reverse phase chromatogram shows single sharp peak showing that the protein is pure and homogeneous.

Protein purity and structural homogeneity is analysed by reversed phase chromatography. 50 µg of protein, at 0.1 mg/ml in 10 mM HCl is analysed in ACE C4 4.6 x 250 mm column using eluted using a 10 – 90 % acetonitrile gradient in 0.1 % trifluoroacetic acid . Homogeneity is judged by the absence of multiple peaks and by the symmetry of the main peak. Blue line shows absorbance at 280 nm and the green line the acetonitrile gradient.

Result: UV spectrum shows full recovery of protein following aliquoting and lyophilisation.

Absorbance at 280 nm: average 0.136

Recovered concentration: 0.136 cm-1 x 10 / 1.46 cm-1 mg ml-1 = 0.93 mg / ml
Recovery: 93%

The sample was reconstituted in 10 mM HCl to a theoretical concentration of 1 mg/ml following instructions above. This was diluted 1:10 in 6 M guanidine hydrochloride, 20 mM sodium phosphate pH 7.4 and the UV spectrum 340-220 nm. Concentration was calculated using extinction coefficient at 280 nm.

Result: Endotoxin level <0.005 EU/ug protein (below level of detection)

Stem cell cultures are sensitive to endotoxins1, which can be present in media, serum and as a contaminant on plasticware.  We optimise our protein production processes to ensure the lowest possible levels of endotoxin contamination.    Our endotoxin pass criteria are set at the industry leading <0.1 EU per ug protein and we aim for <0.01 EU per ug protein.  Endotoxin levels in our proteins are determined by an external expert microbiological testing services provider.

1. A biological study establishing the endotoxin limit for in vitro proliferation of human mesenchymal stem cells (2017). Yusuke Nomura, Chie Fukui, Yuki Morishita, Yuji Haishima. Regenerative Therapy, 7, 45-51.

View units sizes available and purchasing information online or email orders@qkine.com

Our products are for research use only and not for diagnostic or therapeutic use.  Products are not for resale.