The role of bestatin, an inhibitor of cell surface proteases, in the interaction of serum with untransformed cells in culture.

Bestatin is an inhibitor of cell surface-associated aminopeptidase B and leucine aminopeptidase. This microbial product simulates the role of serum as an activator of uridine uptake in quiescent BHK cells. The compound significantly stimulates the incorporation of labelled thymidine into the acid-insoluble fraction of serum-starved Nil 8 cells in the presence of low concentration of serum. The possible mechanisms of these interactions are discussed.