CBP501 Affinity Peptide
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CBP501 Affinity Peptide

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CBP501 Affinity Peptide exhibits similarity to part of the human 14-3-3e αC helix, suggesting that CBP501 may bind to this region.

Category
Others
Catalog number
BAT-014806
CAS number
1351804-17-5
Molecular Formula
C68H119N21O25S
Molecular Weight
1662.89
IUPAC Name
(2S)-2-[[(2S)-6-amino-2-[[(2S)-5-amino-2-[[(2S)-2-[[(2S,3S)-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S,3S)-2-[[(2S,3S)-2-[[(2R)-2-[[3-carboxy-2-[[(2S)-2-[[(2S)-2,4-diamino-4-oxobutanoyl]amino]-3-hydroxypropanoyl]amino]propanoyl]amino]-3-sulfanylpropanoyl]amino]-3-methylpentanoyl]amino]-3-methylpentanoyl]amino]-3-hydroxypropanoyl]amino]-5-(diaminomethylideneamino)pentanoyl]amino]hexanoyl]amino]-3-methylpentanoyl]amino]-4-carboxybutanoyl]amino]-5-oxopentanoyl]amino]hexanoyl]amino]pentanedioic acid
Synonyms
H-Asn-Ser-Asp-Cys-Ile-Ile-Ser-Arg-Lys-Ile-Glu-Gln-Lys-Glu-OH; L-Glutamic acid, L-asparaginyl-L-seryl-L-α-aspartyl-L-cysteinyl-L-isoleucyl-L-isoleucyl-L-seryl-L-arginyl-L-lysyl-L-isoleucyl-L-α-glutamyl-L-glutaminyl-L-lysyl-
Appearance
White Powder
Purity
≥95%
Density
1.51±0.1 g/cm3 (Predicted)
Sequence
NSDCIISRKIEQKE
Storage
Store at -20°C
Solubility
Soluble in Acetic Acid, DMSO
InChI
InChI=1S/C68H119N21O25S/c1-7-32(4)51(64(110)81-40(19-22-48(94)95)58(104)80-39(18-21-46(72)92)57(103)77-36(15-10-12-24-69)56(102)82-41(67(113)114)20-23-49(96)97)87-59(105)37(16-11-13-25-70)78-55(101)38(17-14-26-76-68(74)75)79-61(107)44(30-91)85-65(111)52(33(5)8-2)89-66(112)53(34(6)9-3)88-63(109)45(31-115)86-60(106)42(28-50(98)99)83-62(108)43(29-90)84-54(100)35(71)27-47(73)93/h32-45,51-53,90-91,115H,7-31,69-71H2,1-6H3,(H2,72,92)(H2,73,93)(H,77,103)(H,78,101)(H,79,107)(H,80,104)(H,81,110)(H,82,102)(H,83,108)(H,84,100)(H,85,111)(H,86,106)(H,87,105)(H,88,109)(H,89,112)(H,94,95)(H,96,97)(H,98,99)(H,113,114)(H4,74,75,76)/t32-,33-,34-,35-,36-,37-,38-,39-,40-,41-,42?,43-,44-,45-,51-,52-,53-/m0/s1
InChI Key
LARHMULVOQBFHL-JVQRZWKJSA-N
Canonical SMILES
CCC(C)C(C(=O)NC(CCC(=O)O)C(=O)NC(CCC(=O)N)C(=O)NC(CCCCN)C(=O)NC(CCC(=O)O)C(=O)O)NC(=O)C(CCCCN)NC(=O)C(CCCN=C(N)N)NC(=O)C(CO)NC(=O)C(C(C)CC)NC(=O)C(C(C)CC)NC(=O)C(CS)NC(=O)C(CC(=O)O)NC(=O)C(CO)NC(=O)C(CC(=O)N)N
1. CBP501-calmodulin binding contributes to sensitizing tumor cells to cisplatin and bleomycin
Naoki Mine, Sayaka Yamamoto, Naoya Saito, Satoshi Yamazaki, Chikako Suda, Machiyo Ishigaki, Donald W Kufe, Daniel D Von Hoff, Takumi Kawabe Mol Cancer Ther. 2011 Oct;10(10):1929-38. doi: 10.1158/1535-7163.MCT-10-1139. Epub 2011 Aug 10.
CBP501 is an anticancer drug currently in randomized phase II clinical trials for patients with non-small cell lung cancer and malignant pleural mesothelioma. CBP501 was originally described as a unique G(2) checkpoint-directed agent that binds to 14-3-3, inhibiting the actions of Chk1, Chk2, mitogen-activated protein kinase-activated protein kinase 2, and C-Tak1. However, unlike a G(2) checkpoint inhibitor, CBP501 clearly enhances the accumulation of tumor cells at G(2)-M phase that is induced by cisplatin or bleomycin at low doses and short exposure. By contrast, CBP501 does not similarly affect the accumulation of tumor cells at G(2)-M that is induced by radiation, doxorubicin, or 5-fluorouracil treatment. Our recent findings point to an additional mechanism of action for CBP501. The enhanced accumulation of tumor cells at G(2)-M upon combined treatment with cisplatin and CBP501 results from an increase in intracellular platinum concentrations, which leads to increased binding of platinum to DNA. The observed CBP501-enhanced platinum accumulation is negated in the presence of excess Ca(2+). Some calmodulin inhibitors behave similarly to, although less potently than, CBP501. Furthermore, analysis by surface plasmon resonance reveals a direct, high-affinity molecular interaction between CBP501 and CaM (K(d) = 4.62 × 10(-8) mol/L) that is reversed by Ca(2+), whereas the K(d) for the complex between CBP501 and 14-3-3 is approximately 10-fold weaker and is Ca(2+) independent. We conclude that CaM inhibition contributes to CBP501's activity in sensitizing cancer cells to cisplatin or bleomycin. This article presents an additional mechanism of action which might explain the clinical activity of the CBP501-cisplatin combination.
2. Screening of a library of T7 phage-displayed peptides identifies alphaC helix in 14-3-3 protein as a CBP501-binding site
Yuki Matsumoto, et al. Bioorg Med Chem. 2011 Dec 1;19(23):7049-56. doi: 10.1016/j.bmc.2011.10.004. Epub 2011 Oct 7.
CBP501 is a chemically modified peptide composed of twelve unnatural d-amino acids, which inhibits Chk kinase and abrogates G2 arrest induced by DNA-damaging agents. Here we identified an alphaC helix in 14-3-3 protein as a CBP501-binding site using T7 phage display technology. An affinity selection of T7 phage-displayed peptide using biotinylated CBP501 identified a 14-mer peptide NSDCIISRKIEQKE. This peptide sequence showed similarity to a portion of the alphaC helix of human 14-3-3ε, suggesting that CBP501 may bind to this region. Surface plasmon resonance (SPR) and ELISA demonstrated that CBP501 interacts with 14-3-3ε specifically at the screen-guided region. An avidin-agarose bead pull-down assay showed that CBP501 also binds to other 14-3-3 isoforms in Jurkat cells. Among the other known Chk kinase inhibitors tested, CBP501 showed the strongest affinity for 14-3-3ε. Thus, we conclude that in addition to the direct inhibition of Chk kinase activity, CBP501 directly binds to cellular 14-3-3 proteins through alphaC helix.
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