Genetically encoded discovery of perfluoroaryl macrocycles that bind to albumin and exhibit extended circulation in vivo
Jeffrey Y. K. Wong, Arunika I. Ekanayake, Serhii Kharchenko, Steven E. Kirberger, Ryan Qiu, Payam Kelich, Susmita Sarkar, Jiaqian Li, Kleinberg X. Fernandez, Edgar R. Alvizo-Paez, J. Miao, Shiva Kalhor‐Monfared, J. Dwyer John, Hongsuk Kang, Hwanho Choi, John M. Nuss, John C. Vederas, Yu‐Shan Lin, Matthew S. Macauley, Lela Vuković, William C. K. Pomerantz, Ratmir Derda
Abstract
Abstract Peptide-based therapeutics have gained attention as promising therapeutic modalities, however, their prevalent drawback is poor circulation half-life in vivo. In this paper, we report the selection of albumin-binding macrocyclic peptides from genetically encoded libraries of peptides modified by perfluoroaryl-cysteine S N Ar chemistry, with decafluoro-diphenylsulfone ( DFS ). Testing of the binding of the selected peptides to albumin identified SICRFFC as the lead sequence. We replaced DFS with isosteric pentafluorophenyl sulfide ( PFS ) and the PFS -SICRFFCGG exhibited K D = 4–6 µM towards human serum albumin. When injected in mice, the concentration of the PFS -SICRFFCGG in plasma was indistinguishable from the reference peptide, SA-21. More importantly, a conjugate of PFS -SICRFFCGG and peptide apelin-17 analogue (N 3 -PEG 6 -NMe17A2) showed retention in circulation similar to SA-21; in contrast, apelin-17 analogue was cleared from the circulation after 2 min. The PFS -SICRFFC is the smallest known peptide macrocycle with a significant affinity for human albumin and substantial in vivo circulation half-life. It is a productive starting point for future development of compact macrocycles with extended half-life in vivo.