Identification of a β3-peptide HIV fusion inhibitor with improved potency in live cells

We recently reported a beta(3)-decapeptide, beta WWI-1, that binds a validated gp41 model in vitro and inhibits gp41-mediated fusion in cell culture. Here we report six analogs of beta WWI-1 containing a variety of non-natural side chains in place of the central tryptophan of the WWI-epitope. These analogs were compared on the basis of both gp41 affinity in vitro and fusion inibition in live, HIV-infected cells. One new beta(3)-peptide, beta WXI-a, offers a significantly improved CC50/EC50 ratio in the live cell assay. (C) 2009 Elsevier Ltd. All rights reserved.