An investigation into the heparin-binding properties of a synthetic peptide deduced from the antigenic domain 2 of human cytomegalovirus glycoproteinB

An investigation was performed into the heparin-binding properties of a syn thetic peptide deduced from the sequence of human cytomegalovirus glycoprot ein B. The peptide, T7-13:3, amino acids 69-78, which was previously shown to contain a neutralization epitope was able to bind heparin coated onto mi crotitre plates as well as immobilized on agarose beads. Conversely, labell ed heparin could be used to specifically detect the immobilized peptide. Th e peptide bound to human cells in a manner which suggested an interaction w ith extracellular matrix, and binding of the peptide to human fibroblasts c ould be inhibited both by adding soluble heparin and by enzymatic pretreatm ent of the cells with heparinase. The sequence of T7-13:3 shows similarity to several proteins with known or supposed ability to bind heparin, e.g. ba sic fibroblast growth factor, the heparin-binding capacity of which could a lso be inhibited by T7-13:3. The peptide was also found to bind DNA, probab ly due to the similarities between DNA and heparin in terms of structure an d charge. Because heparin is a chemical homologue of heparan sulfate, the r esults strongly indicate that the sequence represented by T7-13:3 is involv ed in the binding of virus to cell surface heparan sulfate. The described r egion of gB may have the potential to contribute to a subunit vaccine altho ugh possible hazards, such as the induction of auto-antibodies to heparin, and thus also to DNA, need to be considered.