Albumin binding Nanofitins, a new scaffold to extend half-life of biologics – a case study with exenatide peptide

Enhancing Oral Delivery of Biologics: A Non-Competitive and Cross-Reactive Anti-Leptin Receptor Nanofitin Demonstrates a Gut-Crossing Capacity in an Ex Vivo Porcine Intestinal Model

“…Similar EC 50 values were obtained on the rhLepR for 1-F08, whether tested as a monomer or as a dimeric construct ( Table S3 ), indicating consistent binding activity on the rhLepR. Furthermore, the low EC 50 obtained for HSA aligns with the reported high affinity of this Nanofitin for HSA [ 28 ]. Thus, both Nanofitins conserved their respective binding activities in genetic fusion.…”

“…The ability of 1-F08 to transport a cargo protein was also evaluated by fusing the anti-LepR Nanofitin with a second Nanofitin (NF2) specific to HSA [ 28 ], serving as a model protein for potential carriage by the shuttle. We assessed the binding activity of 1-F08-NF2 on the rhLepR and HSA by ELISA.…”

“…These small single-chain binding proteins of 7 kDa, devoid of cysteine residues, are derived from the naturally hyper thermostable protein Sac7d [ 25 , 26 ], or more generally from the Sul7d family [ 27 ]. They can be custom-engineered for high specificity and affinity toward a target, as already demonstrated against a variety of biological targets [ 28 , 29 , 30 , 31 ]. Importantly, they maintain the stability of their parental protein, including resistance to extreme pH levels (pH 1–13) and the harsh intestinal environment [ 28 ].…”

“…They can be custom-engineered for high specificity and affinity toward a target, as already demonstrated against a variety of biological targets [ 28 , 29 , 30 , 31 ]. Importantly, they maintain the stability of their parental protein, including resistance to extreme pH levels (pH 1–13) and the harsh intestinal environment [ 28 ]. With their N- and C-termini located on opposite faces of their binding site, they can be easily assembled to a cargo molecule, either via chemical conjugation or genetic fusion, while preserving their individual properties [ 32 ].…”

Engineering of a Bispecific Nanofitin with Immune Checkpoint Inhibitory Activity Conditioned by the Cross-Arm Binding to EGFR and PDL1

“…Nanofitins are small (66 amino acids, 7 kDa), single-chain, hyperthermostable affinity proteins derived from Sac7d [ 11 ], a histone-like protein composed of a β-barrel capped on the back with a C-terminal α-helix and isolated from the hyperthermophilic archaeon Sulfolobus Acidocaldarius . Libraries of Nanofitins result from the randomization of the natural DNA-binding site of Sac7d, from which high-specificity binders to different molecules can be selected [ 12 , 13 , 14 , 15 , 16 ]. Nanofitins exhibit very high stability in a wide range of temperatures and pH [ 17 , 18 ].…”