Rational optimization of the binding affinity of CD4 targeting peptidomimetics with potential anti HIV activity.
We recently reported the design and synthesis of a CD4 binding peptidomimetic with potential as HIV entry inhibitor. Variation of side chains and amino terminus provided first structure-activity relationships and confirmed the activity of the compounds as well as the correctness of our approach [Neffe, A. T.; Bilang, M.; Meyer, B. Org. Biomol. Chem. 2006, 4, 3259-3267]. Here we describe optimizations at the carboxy terminus of the peptidomimetic CD4 ligands resulting in the highest binding affinity of KD = 6 microM for compound 4 determined with surface plasmon resonance (SPR). Saturation transfer difference NMR experiments with two peptidomimetics give binding constants similar to the SPR experiments and verified the ligand binding epitope. The higher proteolytic stability of the peptidomimetics compared to the lead peptide is demonstrated in a pronase digestion assay. Comparison of modeling and analytical data shows good agreement of theoretical and practical experiments.
Neffe
Axel T
AT
Institute for Organic Chemistry, University of Hamburg, Martin Luther King Platz 6, 20146 Hamburg, Germany. axel.neffe@gkss.de
Bilang
Matthias
M
Grüneberg
Ilona
I
Meyer
Bernd
B
D019380:Anti-HIV Agents / Q000138:chemical synthesis* / Q000737:chemistry; D015704:CD4 Antigens / Q000737:chemistry* / Q000378:metabolism; D004355:Drug Stability; D000939:Epitopes; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D018716:Molecular Mimicry; D009281:Naphthalenes / Q000138:chemical synthesis* / Q000737:chemistry; D009842:Oligopeptides / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D011485:Protein Binding; D013329:Structure-Activity Relationship; D020349:Surface Plasmon Resonance
D019380:Anti-HIV Agents; D015704:CD4 Antigens; D000939:Epitopes; D008024:Ligands; D009281:Naphthalenes; D009842:Oligopeptides; D010455:Peptides