Recombinant Human L-Selectin

L-selectin, also known as CD62L, is a cell adhesion molecule consisting of a large, highly glycosylated, extracellular domain¹ found on leukocytes. It belongs to the selectin family of proteins, which recognise sialylated carbohydrate groups. L-selectin acts as a "homing receptor" for leukocytes to enter secondary lymphoid tissues via the high endothelial venules. L-selectin is an effective marker for separating lymphoid progenitors from myeloid progenitors and hematopoietic stem cells in bone marrow.²

The biological activity of Human L-Selectin was determined by the ability of the immobilized protein to support the adhesion of LS180 cells, a human colon adenocarcinoma cell line. When 1 x 10⁴ cells/well are added to human L-Selectin coated plates (10 μg/ml with 100 μl/well), approximately 90 - 100% will adhere for 1 hour incubation at RT.

The extracellular domain of human L-Selectin (amino acid residues 1 - 332) (Siegelman, M.H. et al., 1989, Proc. Natl. Acad. Sci. USA 86:5562 - 5566; Tedder, T.F. et al., 1989, J. Exp. Med. 170:123 - 133; Camerini, D. et al., 1989, Nature 342:78 - 82) was fused to the carboxy-terminal 6X histidine-tagged Fc region of human IgG1 via a polypeptide linker, inserted into a suitable mammalian expression vector and expressed in NSO cells.

Trp39

Lyophilized

The predicted molecular weight of Recombinant Human L-Selectin is Mr 60.4 kDa. However, the actual molecular weight as observed by migration on SDS Page is Mr 90-100 kDa under reducing conditions.

60.4

This recombinant protein was 0.2 µm filtered and lyophilized from modified Dulbecco’s phosphate buffered saline (1X PBS) pH 7.2 – 7.3 with no calcium, magnesium, or preservatives.

This lyophilized protein is stable for six to twelve months when stored desiccated at -20°C to -70°C. After aseptic reconstitution, this protein may be stored at 2°C to 8°C for one month or at -20°C to -70°C in a manual defrost freezer. Avoid Repeated Freeze Thaw Cycles. See Product Insert for exact lot specific storage instructions.

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1. Levy, K. et al. (2005) J. Cell Mol. Med. 9: 255
2. Spangrude, GJ. et al.(2004) Blood. 103: 2990