ALFA-tag peptide

ALFA-tag peptide

• COA/MS/HPLC Report
• Handling and Storage of Synthetic Peptides
• Material Safety Data Sheets (MSDS)

Batch to batch variation of the purity

H-SRLEEELRRRLTE-OH

H-Ser-Arg-Leu-Glu-Glu-Glu-Leu-Arg-Arg-Arg-Leu-Thr-Glu-OH

13

99.19%

C₆₉H₁₂₃N₂₅O₂₄

1686.86

Synthetic

Powder

The sequence of the minimal ALFA-tag (SRLEEELRRRLTE) is inspired by an artificial peptide (SRLEEELRRRL) reported to form a stable α-helix in solution24. It was selected based on the following criteria: (i) It features a high alpha-helical content, (ii) The sequence is absent in common eukaryotic model systems, (iii) It is hydrophilic and neutral at physiological pH while retaining moderate hydrophobic surfaces and (iv) It does not contain any primary amines that are modified by aldehyde-containing fixatives. The additional Thr-Glu (TE) dipeptide was added to the original peptide to neutralize its positive net charge and thus fully comply with the selection criteria defined above. To minimize any potential influence of neighboring secondary structures, the minimal ALFA-tag sequence was in addition framed by prolines.

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

• Götzke, H., Kilisch, M., Martínez-Carranza, M. et al. The ALFA-tag is a highly versatile tool for nanobody-based bioscience applications. Nat Commun 10, 4403 (2019).

Trifluoroacetic acid (TFA) is a common counterion from the purification process using High-Performance Liquid Chromatography (HPLC). The presence of TFA can affect the peptide's net weight, appearance, and solubility.

Impact on Net Weight: The TFA salt contributes to the total mass of the product. In most cases, the peptide content constitutes >80% of the total weight, with TFA accounting for the remainder.

Solubility: TFA salts generally enhance the solubility of peptides in aqueous solutions.

In Biological Assays: For most standard in vitro assays, the residual TFA levels do not cause interference. However, for highly sensitive cellular or biochemical studies, please be aware of its presence.