Figure 4.

Identification of a target molecule in mouse endothelial cells (bEND.3). The total protein lysate (lane 1) or membrane preparation (lane 2) was separated by SDS-polyacrylamide gel electrophoresis then transferred to nitrocellulose membrane. The latter was probed with biotinylated peptide CAPGPSKSC. Two sharp bands are observed on a Western blot of a whole cell lysate of mouse endothelial cell line (bEND.3). The protein bands bound by the CAPGPSKSC peptide were ∼82 kd and ∼120 kd. The sharpness of the detected bands suggests that these target proteins are not glycosylated. The ∼82-kd protein was also more abundant in cellular fractions enriched for membrane proteins by Triton X-114 extraction, consistent with a membrane localization of this protein.