CD4 Fragment Recombinant Protein

CD4 is a member of the immunoglobulin superfamily and is implicated as associative recognition element in MHC (Major Histocompatibility Complex) class II-restricted immune response (1) . On T-lymphocytes, it defines the helper/inducer subset. The mature 55 kd CD4 protein consists of a 372 amino acid extracellular segment composed of four tandem immunoglobulin-like VJ regions. The CD4 molecule is a major receptor for human immunodeficiency virus (HIV), binding directly to the envelope glycoprotein gp120 on HIV, with the co-receptors being CCR5 or CXCR4. It has been shown that the V-like domains are critical for binding with HIV envelope gp120 (2) . This soluble CD4 fragment (sCD4) will work in HIV neutralization assays at levels comparable to previously published results. The minor upper band seen in the Coomassie blue-stained gel is likely to be due to the presence of uncleaved signal sequence.

Store in working aliquots at -70˚ C. Avoid freeze/thaw cycles. When working with proteins care should be taken to keep recombinant protein at a cool and stable temperature.