HIV Fusion InhibitorsHIV Envelope Protein gp41HIV-1Peptide FragmentsVirus InternalizationMembrane FusionHIV InfectionsDrug DesignSmall Molecule LibrariesDrug Resistance, ViralPeptidesCell FusionAnti-HIV AgentsMolecular Sequence DataAmino Acid SequenceProtein Structure, SecondaryHIVViral Fusion ProteinsRecombinant Fusion ProteinsInhibitory Concentration 50Cell Line