Polysialic acid (PSA), abundant on the neural cell adhesion molecule (NCAM) during embryonic development, acts as an anti-adhesive glycan to negatively modulate the adhesive properties of NCAM (1). PSA expression decreases promptly after birth, and becomes restricted to the hippocampus, hypothalamus, and olfactory bulb, areas of the brain that require continuous cell migration and synaptic plasticity (2). Expression of PSA in cancer cells has been suggested to increase tumor invasiveness and to promote tumor growth (3). The temporal regulation of PSA is dependent on the expression of two polysialyltransferases, ST8SIA4 and ST8SIA2 (4, 5). ST8SIA2, also known as sialyltransferase X, is mainly expressed during embryonic development (4) and shows strict preference on NCAM (6). The high degree of substrate specificity is achieved through specific enzyme-substrate recognition at both the protein sequence and glycan structure levels (6, 7). Like most glycosyltransferases, ST8SIA2 is a Golgi-resident type II membrane protein. The activity of this enzyme has been measured with a phosphatase-coupled method (8).
Recombinant protein corresponding to Asp24-Thr375 from human a-2,8-Sialyltransferase 8B/ST8SIA2, fused with 6-His tag at N-terminal, expressed in mouse myeloma cell line, NSO cells.
Molecular Weight:~41kD
Biological Activity:Measured by its ability to transfer sialic acid from CMP-NeuAc to recombinant human CD56. The specific activity is >85pmol/min/ug, as measured under the described conditions.
Storage and Stability:May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for 6 months after receipt at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
仕様
Size：20ug
Source Antigen：Recombinant, NSO
Grade：Highly Purified
Purity：≥95% (SDS-PAGE). Endotoxin: ≤1EU/1ug (LAL)
Form：Supplied as a liquid in Tris, sodium chloride.
