DOTATATE peptide

DOTATATE peptide

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

Batch to batch variation of the purity

DOTA-fCYwKTCT-OH (f=D-Phe, w=D-Trp, Disulfide bridge:Cys2-Cys7)

DOTA-D-Phe-Cys-Tyr-D-Trp-Lys-Thr-Cys-Thr-OH

8

95.98%

C₆₅H₉₀N₁₄O₁₉S₂

1435.61

177943-88-3

11170867

Synthetic

Powder

DOTATATE is a synthetic peptide used primarily in nuclear medicine for both diagnostic and therapeutic purposes, particularly targeting tumors that express somatostatin receptors. It is a derivative of octreotate, a somatostatin analogue, and is modified to allow the attachment of radioactive isotopes, such as gallium-68 or lutetium-177. When radiolabeled (e.g., Ga-68 DOTATATE), the peptide binds specifically to somatostatin receptor subtype 2 (SSTR2), which is overexpressed in many neuroendocrine tumors.

Key points about DOTATATE:

- It has a high affinity for SSTR2, making it highly effective for imaging and targeting tumors.

- It is commonly used in PET imaging to detect neuroendocrine tumors and can also be used in radionuclide therapy (e.g., using lutetium-177 for treatment).

- Radiolabeled DOTATATE provides clearer tumor imaging and allows for precise targeting in radiotherapy due to its strong binding to tumor cells that express somatostatin receptors.

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

• Reubi JC, Schär JC, Waser B, Wenger S, Heppeler A, Schmitt JS, Mäcke HR. Affinity profiles for human somatostatin receptor subtypes SST1-SST5 of somatostatin radiotracers selected for scintigraphic and radiotherapeutic use. Eur J Nucl Med. 2000 Mar;27(3):273-82. doi: 10.1007/s002590050034. PMID: 10774879.

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.