DOTA-LM3 peptide

DOTA-LM3 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-Tyr-D-Aph(Cbm)-Lys-Thr-Cys]-D-Tyr-NH2

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

8

95.45%

C₆₉H₉₃ClN₁₆O₁₉S₂

1550.2

1192362-32-5

168355559

Synthetic

Powder

DOTA-LM3, or DOTA-p-Cl-Phe-c[D-Cys-Tyr-D-4-amino-Phe(carbamoyl)-Lys-Thr-Cys]-D-Tyr-NH2, is a somatostatin antagonist peptide that has been studied for its potential in peptide receptor radionuclide therapy (PRRT) for patients with metastatic neuroendocrine neoplasms (NENs). Here is some information about DOTA-LM3:
Binding Affinity and Radiometal Modifications: Studies have shown that the binding affinity of DOTA-LM3 and its metallated conjugates to somatostatin receptors can be influenced by the radiometal. For example, in some cases, different radiometals coupled to DOTA-LM3 can result in changes in its affinity for the receptors.
DOTA-LM3 appears to be promising for PRRT, providing a favorable biodistribution and higher tumor radiation doses than SSTR agonists, and was effective in treating advanced metastatic NENs, especially in patients with low or no SSTR agonist binding, even achieving complete remission in some patients.

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

• Baum RP, Zhang J, Schuchardt C, Müller D, Mäcke H. First-in-Humans Study of the SSTR Antagonist 177Lu-DOTA-LM3 for Peptide Receptor Radionuclide Therapy in Patients with Metastatic Neuroendocrine Neoplasms: Dosimetry, Safety, and Efficacy. J Nucl Med. 2021 Nov;62(11):1571-1581. doi: 10.2967/jnumed.120.258889. Epub 2021 Mar 5. PMID: 33674401; PMCID: PMC8612334.

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.