Purity ~90% (SDS-PAGE). Accessory protein for MHC class-II antigen/T-cell receptor interaction. May regulate T-cell activation. Induces the aggregation of lipid rafts. (Microbial infection) Acts as a receptor for human immunodeficiency virus-1. Source: Recombinant protein corresponding to aa26-396 from human CD4, fused to His-Tag at N-terminal, expressed in Yeast. Molecular Weight: ~43.3kD AA