A TfR-Binding Cystine-Dense Peptide Promotes Blood–Brain Barrier Penetration of Bioactive Molecules. Issue 14 (26th June 2020)

• Record Type: Journal Article
• Authors: Crook, Zachary R.; Girard, Emily; Sevilla, Gregory P.; Merrill, Morgan; Friend, Della; Rupert, Peter B.; Pakiam, Fiona; Nguyen, Elizabeth; Yin, Chunfeng; Ruff, Raymond O.; Hopping, Gene; Strand, Andrew D.; Finton, Kathryn A.K.; Coxon, Margo; Mhyre, Andrew J.; Strong, Roland K.; Olson, James M.
• Is Part Of: Journal of molecular biology. Volume 432:Issue 14(2020)
• Page Start: 3989
• Page End: 4009
• Publication Date: 2020-06-26
• Subjects: BBB blood–brain barrier -- CNS central nervous system -- CDP cystine-dense peptide -- TfR transferrin receptor -- SDGF surface display GFP FasL vector -- 293F human embryonic kidney cell line 293 Freestyle -- SSM site-saturation mutagenesis -- TfRB1G [1, 2, or 3] TfR binding CDP, generation [1, 2, or 3] -- HPLC high-performance liquid chromatography -- NT neurotensin -- NTSR1 neurotensin receptor 1 -- CRE cyclic AMP response element; high-throughput screening -- drug discovery -- drug delivery -- protein therapeutics -- central nervous system; Molecular biology -- Periodicals; Biology -- Periodicals; Biochemistry -- Periodicals; Bacteriology -- Periodicals; Molecular Biology -- Periodicals; Biochemistry -- Periodicals; Biologie moléculaire -- Périodiques; Biologie -- Périodiques; Biochimie -- Périodiques; Moleculaire biologie; Biochemistry; Biology; Molecular biology; Periodicals; 572.805
• DOI: 10.1016/j.jmb.2020.04.002
• Languages: English
• ISSNs: 0022-2836

Abstract

Abstract: The impenetrability of the blood–brain barrier (BBB) to most conventional drugs impedes the treatment of central nervous system (CNS) disorders. Interventions for diseases like brain cancer, neurodegeneration, or age-associated inflammatory processes require varied approaches to CNS drug delivery. Cystine-dense peptides (CDPs) have drawn recent interest as drugs or drug-delivery vehicles. Found throughout the phylogenetic tree, often in drug-like roles, their size, stability, and protein interaction capabilities make CDPs an attractive mid-size biologic scaffold to complement conventional antibody-based drugs. Here, we describe the identification, maturation, characterization, and utilization of a CDP that binds to the transferrin receptor (TfR), a native receptor and BBB transporter for the iron chaperone transferrin. We developed variants with varying binding affinities ( K D as low as 216 pM), co-crystallized it with the receptor, and confirmed murine cross-reactivity. It accumulates in the mouse CNS at ~ 25% of blood levels (CNS blood content is only ~ 1%–6%) and delivers neurotensin, an otherwise non-BBB-penetrant neuropeptide, at levels capable of modulating CREB signaling in the mouse brain. Our work highlights the utility of CDPs as a diverse, easy-to-screen scaffold family worthy of inclusion in modern drug discovery strategies, demonstrated by the discovery of a candidate CNS drug delivery vehicle ready for further optimization and preclinical development. Graphical abstract: Unlabelled Image Highlights: Blood–brain barrier penetration is key to treating central nervous system diseases. A drug-like cystine-dense peptide that binds transferrin receptor was identified. Brain accumulation and pharmacodynamic effect of peptide cargo were seen. This peptide represents a small (5 kDa) tag permitting CNS delivery of therapeutics.