Synthetic peptides of hIR-B were purchased from CPC Scientific..
Abstract
Insulin receptor (IR) phosphorylation is critical for the assessment of the extent of IR agonism and nuances in the downstream signaling cascade. A thorough identification and monitoring of the phosphorylation events is important for understanding the process of insulin signaling transduction and regulation. Although IR phosphorylation has been studied extensively in the past decades, only a handful of phosphorylation sites can be identified by either traditional antibody-based assays or recent large-scale mass spectrometry-based phosphoproteomics approaches. In the present study, the most exhaustive assessment of the IR phosphorylation was conducted using nano-liquid chromatography-tandem mass spectrometry, in which 13 IR phosphorylation sites and 22 combinations thereof were analyzed. The kinetic analysis included Y965, Y972, S968/969, and S974/976 in the juxtamembrane region; Y1158, Y1162, and Y1163 in the kinase domain; and Y1328, Y1334, S1278, S1320, S1321, and T1348 in the C-terminal region. Employing two different receptor agonists (i.e. insulin and an IR peptide agonist), the data revealed contrasting phosphorylation kinetics across these sites with dynamics far more diverse than expected for known IR agonists. Notably, cell trafficking experiments revealed that the IR peptide agonist was incapable of inducing IR to the early endosome, which is probably linked to a difference in IR phosphorylation. The present study provides a powerful tool for investigating IR signaling and trafficking that will benefit the design of IR agonists with improved therapeutic utility.
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 […]