Selectins are a family of calcium-dependent type 1 transmembrane proteins. Endothelial (E)-selectin is a heavily glycosylated transmembrane protein expressed by activated endothelial cells in microvascular linings. E-selectin, along with P-selectin and L-selectin, initiate recruitment of circulating leukocytes from blood to sites of inflammation in the vascular lining through interaction with specific cell surface associated carbohydrate determinants. E-selectin consists of an N-terminal type 1 lectin domain, an EGF-like domain, 6 sushi (CCP/SCR) domains, a transmembrane sequence, and a short cytoplasmic domain. Recombinant human E-selectin is a 58.6 kDa protein containing 535 amino acid residues, corresponding to the extracellular portion of the full length protein. Due to glycosylation, E-selectin migrates at an apparent molecular weight of approximately 65-85 kDa by SDS-PAGE analysis under reducing conditions.