"..folded HD5 was generated from a synthesized 80% pure linear peptide (CPC Scientific, Sunnyvale, CA) by thiol disulfide reshuffling overnight at room temperature in the presence of 3 mM reduced and 0.3 mM oxidized glutathione, 2 M guanidine hydrochloride, and 0.25 M sodium bicarbonate, pH 8.3, at a peptide concentration of 0.25 mg/ml [..] All α-defensins were quantified by UV absorbance at 280 nm using calculated molar extinction coefficients (18)."
Abstract
Human α-defensins, such as human α-defensin 5 (HD5), block infection of non-enveloped viruses, including human adenoviruses (AdV), papillomaviruses (HPV), and polyomaviruses. Through mutational analysis of HD5, we have identified arginine residues that contribute to antiviral activity against AdV and HPV. Of two arginine residues paired on one face of HD5, Arg-28 is critical for both viruses, while Arg-9 is only important for AdV. Two arginine residues on the opposite face of the molecule (Arg-13 and Arg-32) and unpaired Arg-25 are less important for both. In addition, hydrophobicity at residue 29 is a major determinant of anti-adenoviral activity, and a chemical modification that prevents HD5 self-association was strongly attenuating. Although HD5 binds to the capsid of AdV, the molecular basis for this interaction is undefined. Capsid binding by HD5 is not purely charge-dependent, as substitution of lysine for Arg-9 and Arg-28 was deleterious. Analysis of HD5 analogs that retained varying levels of potency demonstrated that anti-adenoviral activity is directly correlated with HD5 binding to the virus, confirming that the viral capsid rather than the cell is the relevant target. Also, AdV aggregation induced by HD5 binding is not sufficient for neutralization. Rather, these studies confirm that the major mechanism of HD5-mediated neutralization of AdV depends upon specific binding to the viral capsid through interactions mediated in part by critical arginine residues, hydrophobicity at residue 29, and multimerization of HD5, which increases initial binding of virus to the cell but prevents subsequent viral uncoating and genome delivery to the nucleus.
SOCIAL MEDIA
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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 […]