A peptide designed to encompass VEGFR2 residues 786-805 was synthesized and purified to 98% purity (CPC Scientific, San Jose, CA). Compounds were synthesized as described in patents: AG-13736 (35), AG-13974 (36), AG-28038 (35), and AG-28047 (37).
Abstract
The catalytic domains of protein kinases are commonly treated as independent modular units with distinct biological functions. Here, the interactions between the catalytic and juxtamembrane domains of VEGFR2 are studied. Highly purified preparations of the receptor tyrosine kinase VEGFR2 catalytic domain without (VEGFR2-CD) and with (VEGFR2-CD/JM) the juxtamembrane (JM) domain were characterized by kinetic, biophysical, and structural methods. Although the catalytic parameters for both constructs were similar, the autophosphorylation rate of VEGFR2-CD/JM was substantially faster than VEGFR2-CD. The first event in the autophosphorylation reaction was phosphorylation of JM residue Y801 followed by phosphorylation of activation loop residues in the CD. The rates of activation loop autophosphorylation for the two constructs were determined to be similar. The autophosphorylation rate of Y801 was invariant on enzyme concentration, which is consistent with an intramolecular reaction. In addition, the first biochemical characterization of the advanced clinical compound axitinib is reported. Axitinib was found to have 40-fold enhanced biochemical potency toward VEGFR2-CD/JM (Ki = 28 pM) compared to VEGFR2-CD, which correlates better with cellular potency. Calorimetric studies, including a novel ITC compound displacement method, confirmed the potency and provided insight into the thermodynamic origin of the potency differences. A structural model for the VEGFR2-CD/JM is proposed based on the experimental findings reported here and on the JM position in c-Kit, FLT3, and CSF1/cFMS. The described studies identify potential functions of the VEGFR2 JM domain with implications to both receptor biology and inhibitor design.
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CPC Scientific Inc., a leading global peptide CRDMO (Contract Research, Development, and Manufacturing Organization) has invested in a new peptide API (Active Pharmaceutical Ingredient) manufacturing site, bringing many new jobs to Rocklin, California. The 41,000 sq ft facility located at 3880 Atherton Rd, Rocklin, CA 95765 will be utilized to manufacture clinical to commercial grade peptide products for increased manufacturing capacity and will diversify CPC Scientific’s supply chain.
CPC Scientific is entering an exciting period of growth and innovation for peptide and oligonucleotide therapeutic development and manufacturing, and we will continue to provide therapeutic APIs to pharmaceutical and biotech companies around the world. We are very pleased to partner with the City of Rocklin, California to bring manufacturing and Life-Science jobs to local American workers,” said Shawn Lee, PhD, CEO.
Ikeda, Z., Kakegawa, K., Kikuchi, F., Itono, S., Oki, H., Yashiro, H., Hiyoshi, H., Tsuchimori, K., Hamagami, K., Watanabe, M. and Sasaki, M. Journal of Medicinal Chemistry 65, no. 12 (2022): 8456-8477.
- Research, Takeda Pharmaceutical Company Limited, 26-1, Muraokahigashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
Subsequently, 5FAM–Abu–Gly–Asp–Asp–Asp–Lys–Ile–Val–Gly–Gly–Lys(CPQ2)–Lys–Lys–NH2 (purity: 97.2%, CPC Scientific, Inc.) was diluted with an assay buffer to prepare a 2.1 μM substrate solution.
The transferred energy from a fluorescent donor is converted into molecular vibrations if the acceptor is a non-fluorescent dye (quencher). When the FRET is terminated (by separating donor and acceptor), an increase of donor fluorescence can be detected. The design and synthesis work at CPC for FRET and TR-FRET peptide substrates include modification of sequences, selection of donor/quencher pairs, improvement of FRET substrate solubility and quenching efficiency.
Genomics research shows that more than a million proteins are encoded by approximately 30,000 human genes. Proteomics, the study of proteins encoded by the genome, includes identifying post-translational modifications, structural analyses, protein localization studies, and protein quantitation. Mass spectroscopybased techniques have evolved as a powerful tool in proteomics. Stable isotope-labeled peptides (SIL peptides) are chemically and physically indistinguishable from their endogenous counterparts concerning retention time, ionization efficiency, and fragmentation pathways.
Peptides play a vital role in the pharmaceutical industry and drug therapeutic development; however, their in vivo applications are sometimes limited due to fast degradation by proteases, poor solubility, antigenic responses, and glomerular filtration in the kidney. The covalent attachment of polyethylene glycol (PEG) chains to peptides is one approach that can reduce immunogenicity, improve solubility, and reduce renal clearance.
Hydrocarbon-stapled peptides are locked into their bioactive alpha-helical conformation through the site-specific introduction of a chemical brace, an all-hydrocarbon staple. The idea of peptide stapling was introduced to overcome the limitations of two broad classes of therapeutic agents (small molecules and protein biologics) in targeting intracellular protein-protein interactions. Small molecules only work on proteins with a specific surface feature, and most protein biologics do not penetrate cells. Because stapled peptides are locked into a stabilized α-helical structure (the most common element of protein secondary structures), they can easily penetrate cells.
![Locmi-AKH-I, cycloAKH (cyclo[LNFTPNWG]](https://test.cpcscientific.com/wp-content/uploads/2022/05/cyclo-LNFTPNWG-v2-1500sm.png)
Mogford, Jon E., George E. Davis, Steven H. Platts, and Gerald A. Meininger. Circulation research 79, no. 4 (1996): 821-826.
Locmi-AKH-I, cycloAKH (cyclo[LNFTPNWG]
CPC Scientific is pleased to announce and welcome David A. Godkin as VP of Business Operations! David will be responsible for the growth and development of our HR department and facilities management division. He brings 20+ years of experience in human resources and facility operations from the peptide industry. We are confident David will have […]
Bekdemir, Ahmet, Eden EL Tanner, Jesse Kirkpatrick, Ava P. Soleimany, Samir Mitragotri, and Sangeeta N. Bhatia Advanced Healthcare Materials (2022): 2102685.
Peptides [TDN-qFAM, C-(PEG)2-K(CPQ2)-GGGSRPfGG-5FAM] were obtained from Tufts University Peptide Core Facility or CPC Scientific, Inc (USA)
