"To determine the IC50 values of the selected cyclic peptides, we chemically synthesized the peptides C2 and G12 in both linear and cyclic forms (CPC Scientific)."
Abstract
We report a bacterial system for the evolution of cyclic peptides that makes use of an expanded set of amino acid building blocks. Orthogonal aminoacyl-tRNA synthetase/tRNACUA pairs, together with a split intein system were used to biosynthesize a library of ribosomal peptides containing amino acids with unique structures and reactivities. This peptide library was subsequently used to evolve an inhibitor of HIV protease using a selection based on cellular viability. Two of three cyclic peptides isolated after two rounds of selection contained the keto amino acid p-benzoylphenylalanine (pBzF). The most potent peptide (G12: GIXVSL; X = pBzF) inhibited HIV protease through the formation of a covalent Schiff base adduct of the pBzF residue with the ϵ-amino group of Lys 14 on the protease. This result suggests that an expanded genetic code can confer an evolutionary advantage in response to selective pressure. Moreover, the combination of natural evolutionary processes with chemically biased building blocks provides another strategy for the generation of biologically active peptides using microbial systems.
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Solid-phase peptide synthesis (SPPS) has many advantages over liquid-phase peptide synthesis (LPPS) for preparing and manufacturing synthetic peptides. Except the synthesis of short peptide sequences (i.e., less than five amino acid residues), SPPS is faster, more efficient, and more economical than liquid-phase peptide synthesis (LPPS). Some of the advantages of SPPS include: (1) Excess reagents and products can be easily washed away, (2) using excess reagents to increase reaction rates and drive reactions to completion, (3) intermediates do not require isolation or characterization, (4) access to a broader range of solvents with low volatility and high polarity, (5) tethered peptide provides a ‘pseudo-dilute’ microenvironment, which can inhibit intermolecular reactions, making some modifications easier to accomplish, and (6) compatibility with automated synthesis technology.
Lo, J.H., Hao, L., Muzumdar, M.D., Raghavan, S., Kwon, E.J., Pulver, E.M., Hsu, F., Aguirre, A.J., Wolpin, B.M., Fuchs, C.S. and Hahn, W.C. Molecular Cancer Therapeutics 17, no. 11 (2018): 2377-2388.
pTP-TAMRA-iRGD (CH3(CH)15-[GWTLNSAGYLLGKINLKALAALAKKIL-GGK(TAMRA)GGCRGDKGPDC, Cys-Cys bridge]) used in all figures except Fig. S1 was synthesized by CPC Scientific.
Ng, Ee Xien, Myat Noe Hsu, Guoyun Sun, and Chia-Hung Chen. Methods in Enzymology 628 (2019): 59-94.
The peptide sequences of the four FRET-based substrates ([..] CPC Scientific) are as follows: UV: AlexaFluor405-Leu-Ala-Gln-Ala-HompheArg-Ser-Lys (QSY35)-NH2; Blue: Dabcyl-Gly-Pro-Leu-Gly-Met-Arg-Gly-Lys (5-FAM)-NH2; Green: QSY7-Ala-Pro-Phe-Glu..
West, J.A., Tsakmaki, A., Huang, J.H., Ghosh, S.S., Parkes, D.G., Wismann, P., Rigbolt, K.T., Pedersen, P.J., Pavlidis, P., Maggs, D. and Lopez-Talavera, J.C. bioRxiv (2019) 822122.
- Fractyl Laboratories Inc, Lexington, MA, 02421, USA
- Diabetes Research Group, School of Life Course Sciences, Faculty of Life Science and Medicine, King’s College London, London, WC2R 2LS, England, UK
[..] infusion of vehicle 2 via osmotic minipump; (2) glucagon-like peptide-1 receptor (GLP-1R) agonist (0.2 mg/kg liraglutide, SC, QD, Victoza (Novo Nordisk, Bagsværd, Denmark) and continuous infusion of vehicle 2 via osmotic minipump; (3) vehicle 1 (SC, QD) and continuous infusion of a glucose-dependent insulinotropic polypeptide receptor (GIPR) antagonist (∼4.5 mg/kg/day / 56.8 nmol/kg/h GIP[3-30]NH2, CPC Scientific Inc, Sunnyvale, CA, USA) via osmotic minipump;
Artur Javmen, Vladimir Y. Toshchakov, et al. Journal of Leukocyte Biology (2019).
All CPDPs included the N‐terminal Antennapedia homeodomain sequence RQIKIWFQNRRMKWKK.38 The Cy3‐labeled peptides were produced by CPC Scientific (Sunnyvale, CA, USA). The Cy3 label was placed at the peptide N‐terminus..
Gilles, Maud-Emmanuelle, Slack, Frank J, et al. Oncotarget, 2019, Vol. 10, (No. 51), pp: 5349-5358
"Tandem peptide (pTP-iRGD: CH3(CH)15-GWTLNSAGYLLGKINLKALAALAKKIL-GGK(TAMRA)GGCRGDKGPDC, Cys-Cys bridge) was synthesized by CPC Scientific."
Garner, Thomas P., Dulguun Amgalan, Denis E. Reyna, Sheng Li, Richard N. Kitsis, and Evripidis Gavathiotis. Nature Chemical Biology 15, no. 4 (2019): 322.
"Hydrocarbon-stapled peptides corresponding to the BH3 domain of BIM, BIM SAHBA2: N-acetylated- and FITC-Ahx-EIWIAQELRS5IGDS5FNAYYA-CONH2, where S5 represents the non-natural amino acid inserted for olefin metathesis, were synthesized, purified at >95% purity by CPC Scientific Inc. and characterized as previously described."
Gibbs, Ebrima, Judith M. Silverman, Beibei Zhao, Xubiao Peng, Jing Wang, Cheryl L. Wellington, Ian R. Mackenzie, Steven S. Plotkin, Johanne M. Kaplan, and Neil R. Cashman. Scientific Reports 9, no. 1 (2019): 1-14.
The conformational epitope was synthesized as a cyclic peptide with additional N-terminal residues CG and a C-terminal G to recapitulate the predicted structure of HHQK on AβO. Peptide synthesis was performed by CPC Scientific Inc. (Sunnyvale CA, USA) [..] Cyclization was performed via a head-to-tail (C-G) amide bond and c[CGHHQKG] was then conjugated to either keyhole limpet hemocyanin (KLH) or bovine serum albumin (BSA) via maleimide-based coupling.
SUNNYVALE, US. and Hangzhou, China, June 24th, 2019 /CPCNewswire/ — CPC Scientific Inc. and its affiliate Chinese Peptide Company, a public Hangzhou-based CDMO (Stock Symbol: 002390) is pleased to announce today that their GMP manufacturing facility, has successfully passed its inspection by the competent authority of Germany as an“active substance manufacturer that has been inspected […]