Purification and quantification of L-selectin-reactive GlyCAM-1 from mouse serum

GlyCAM-1 is an endothelial-derived mucin found in the conditioned medium of organ-cultured lymph nodes and in serum. It is a ligand for L-selectin, but also interacts with P and E-selectin. It may play a role in the modulation of leukocyte trafficking into secondary lymphoid tissues as well as chronic inflammatory sites. Here we report the development of an ELISA that quantifies GlyCAM-1 in complex biological fluids such as serum. The ELISA response is linear over a concentration range of 13-800 ng/ml. The level of GlyCAM-1 in mouse serum was found to be 1.3-1.6 micrograms/ml. Using mouse serum as starting material, we report a rapid and efficient purification scheme for the isolation of biologically active GlyCAM-1. This material may now be used to address the biological functions of GlyCAM-1 and to further define its structural features.