Analysis Note

The biological activity of recombinant human noggin was tested in culture by measuring its ability to inhibit BMP4-induced alkaline phosphatase production by ATDC5 cells (human erythroleukemic indicator cell line).The EC50 is defined as the effective concentration of growth factor that elicits a 50% decrease in alkaline phosphatase secretion in a cell based bioassay.

Biochem/physiol Actions

Noggin is a secreted protein that inhibits the binding of bone morphogenetic proteins (BMPs) to their cognate receptor. It is a 232 amino acid-secreted glycosylated protein, which forms covalently linked homodimers and has high affinity for BMP4. hESC cultured with noggin (in medium or incorporated into extracellular matrix) form denser colonies compared to normal hESC cultures, suggesting that the presence of noggin promotes better growth. Noggin can be incorporated as a medium supplement for maintaining stem cells in a pluripotent state, for short-term culture experiments. Noggin does not trigger differentiation towards a neuronal lineage. Furthermore, when incorporated into extracellular matrix, noggin prevented spontaneous differentiation during the time period examined. In a surgically induced knee osteoarthritis model in mice, expression of noggin mRNA was lost from the articular cartilage, which correlated with loss of BMP2/4 and pSMAD1/5/8, an indicator of active BMP signaling.

General description

Recombinant human Noggin is expressed in human 293 cells as a glycoprotein with a calculated molecular mass of 23 kDa. This protein is manufactured in human cells using an all-human production system, with no serum. The human cells expression system allows human-like glycosylation and folding, and often supports better stability of the protein in culture.

Physical form

Supplied as a lyophilized powder containing phosphate buffered saline.

Sequence

QHYLHIRPAPSDNLPLVDLIEHPDPIFDPKEKDLNETLLRSLLGGHYDPGFMATSPPEDRPGGGGGAAGGAEDLAELDQLLRQRPSGAMPSEIKGLEFSEGLAQGKKQRLSKKLRRKLQMWLWSQTFCPVLYAWNDLGSRFWPRYVKVGSCFSKRSCSVPEGMVCKPSKSVHLTVLRWRCQRRGGQRCGWIPIQYPIISECKCSC