DOTA-JR11 peptide

DOTA-JR11 peptide

• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

DOTA-Phe(4-Cl)-c[D-Cys-Aph(Hor)-D-Aph(Cbm)-Lys-Thr-Cys]-D-Tyr-NH2

DOTA-Phe(4-Cl)-c[D-Cys-Aph(Hor)-D-Aph(Cbm)-Lys-Thr-Cys]-D-Tyr-NH2

8

95.96%

C₇₄H₉₈ClN₁₉O₂₁S₂

1689.3

1039726-31-2

24894654

Synthetic

Powder

DOTA-JR11 is a somatostatin antagonist peptide that has been studied for its potential in imaging and treating neuroendocrine tumors. Here is some information about DOTA-JR11:
Chemical Structure: DOTA-JR11 has the chemical structure DOTA-Cpa-c[D-Cys-Aph(Hor)-D-Aph(Cbm)-Lys-Thr-Cys]-D-Tyr-NH2.
Binding Affinity: In studies, it was found that the binding affinity of DOTA-JR11 and its metallated conjugates to somatostatin receptors can be influenced by the radiometal. For example, in the JR11 family, yttrium or indium coupling to DOTA retains a high sst2 affinity comparable to the DOTA-JR11 compound without metal, while gallium induces a massive loss of the sst2 affinity. Replacing DOTA by the chelator NODAGA can restore the binding affinity in the case of gallium.
In Vivo Studies: Biodistribution experiments showed that the antagonists Ga-DOTA-JR11 and Ga-NODAGA-JR11 had higher tumor uptake than the agonist 68Ga-DOTATATE in mice bearing HEK-hsst2 tumor xenografts. Additionally, 68Ga-DOTA-JR11 PET can be used for patient selection and PRRT (peptide receptor radionuclide therapy), and low tumor uptake on PET should not preclude patients from treatment with 177Lu-satoreotide tetraxetan, which is a radiolabeled form of DOTA-JR11.
Clinical Significance: The development of somatostatin receptor antagonists like DOTA-JR11 is part of the effort to develop better imaging agents for SPECT/CT and PET/CT and agents for targeted radionuclide therapy of neuroendocrine tumors. The ability to use single time-point SPECT/CT for absorbed dose calculations with 177Lu-satoreotide tetraxetan could facilitate dosimetry regimens, save costs, and improve patient convenience.
Overall, DOTA-JR11 is a promising peptide in the field of neuroendocrine tumor research, and further studies are needed to fully explore its potential.

Normally, this peptide will be delivered in lyophilized form and should be stored in a freezer at or below -20 °C. For more details, please refer to the manual: Handling and Storage of Synthetic Peptides

• Fani M, Braun F, Waser B, Beetschen K, Cescato R, Erchegyi J, Rivier JE, Weber WA, Maecke HR, Reubi JC. Unexpected sensitivity of sst2 antagonists to N-terminal radiometal modifications. J Nucl Med. 2012 Sep;53(9):1481-9. doi: 10.2967/jnumed.112.102764. Epub 2012 Jul 31. PMID: 22851637.
• Krebs S, O'Donoghue JA, Biegel E, Beattie BJ, Reidy D, Lyashchenko SK, Lewis JS, Bodei L, Weber WA, Pandit-Taskar N. Comparison of 68Ga-DOTA-JR11 PET/CT with dosimetric 177Lu-satoreotide tetraxetan (177Lu-DOTA-JR11) SPECT/CT in patients with metastatic neuroendocrine tumors undergoing peptide receptor radionuclide therapy. Eur J Nucl Med Mol Imaging. 2020 Dec;47(13):3047-3057. doi: 10.1007/s00259-020-04832-9. Epub 2020 May 6. PMID: 32378020; PMCID: PMC7644587.

Trifluoroacetic acid (TFA) has a significant impact on peptides due to its role in the peptide synthesis process.

TFA is essential for the protonation of peptides that lack basic amino acids such as Arginine (Arg), Histidine (His), and Lysine (Lys), or ones that have blocked N-termini. As a result, peptides often contain TFA salts in the final product.

TFA residues, when present in custom peptides, can cause unpredictable fluctuations in experimental data. At a nanomolar (nM) level, TFA can influence cell experiments, hindering cell growth at low concentrations (as low as 10 nM) and promoting it at higher doses (0.5–7.0 mM). It can also serve as an allosteric regulator on the GlyR of glycine receptors, thereby increasing receptor activity at lower glycine concentrations.

In an in vivo setting, TFA can trifluoroacetylate amino groups in proteins and phospholipids, inducing potentially unwanted antibody responses. Moreover, TFA can impact structure studies as it affects spectrum absorption.