Cyclic peptides are of considerable interest as potential protein ligands. It has been postulated that cyclic molecules might be more cell permeable than their linear counterparts due to their reduced conformational flexibility. We report a study that tests this hypothesis by using a quantitative, reporter gene-based assay that measures the relative cell permeability of steroid conjugates of molecules of interest. We demonstrate that cyclic peptides are, in fact, not generally more permeable than their linear counterparts.
Bibliographical noteFunding Information:
This work was supported by a contract from the National Heart, Lung, and Blood Institute (NHLBI) (NO1-HV-28185). We thank Dr. Peng Yu, Mr. Jiyong Lee, and Mr. Chiang Tan for technical assistance and helpful discussions, and Dr. Kyung-Jong Lee for assistance with the fluorescence imaging experiment.