In the realm of biochemical research and protein engineering, the selection of an appropriate affinity tag is a critical decision for achieving high-purity results. Among the various tools available Strep-tag® II peptide , the Strep tag ii peptide sequence has become a staple for r Strep II-Tag esearchers looking for efficiency and high specificity. Drawing from my personal experience in laboratory settings, I have found that understanding the nuances of this specific sequence is key to effective protein purification and analysis.
Decoding th The Strep-tag system for one-step purification and high-affinity e Strep-tag II Structure
The Strep-tag II is a synthetic peptide characterized by its small size and high affinity for engineered streptavidin, known as Strep-Tactin. Unlike larger tags that might interfere with protein folding, this eight amino acid fusion tag is remarkably unobtrusive.
The primary peptide sequence is widely recognized in literature as WSHPQFEK. This eight amino acid peptide is the industry standard for those seeking to minimize the impact on the target protein's structure and function. It is important to note that while earlier iterations of the technology utilized a nine-residue sequence (AWRHPQFGG), the optimized eight-residue minimal peptide sequence (WSHPQFEK) is now the preferred choice for most modern applications.
Technical Specifications and Variations
When working with this tag II, precision is paramount. The sequence is often synthesized as a synthetic Strep-tag® II peptide to assist in competitive elution or as a control in blot assays.
* Standard Sequence: WSHPQFEK
* Alternative/Extended Strep-Tag II Monoclonal Antibody Sequence: Some technical data sheets specify SAWSHPQFEK, which includes an additional N-terminal serine and alanine, often used for specific anchoring or structural requirements.
* Molecular Weight: Approximately 1216 Da for the standard synthetic form.
In my own work, I have found that the eight amino acids (WSHPQFEK) long minimal peptide sequence offers a balance of binding strength and ease of elution. When sequencing or verifying the expression of recombinant proteins, ensuring that these sequences are correctly encoded at either the N- or C-terminus is vital.
Practical Applications and Observations
The Strep system is favored for its "one-step" purification capabilities. The interaction between the tag and the Tactin matrix allows for extremely gentle elution conditions compared to other common affinity systems.
One common use case involves utilizing the synthetic Strep-tag® II peptid It can be used for competitive elution ofStrep-tag®IIfusion proteins or as control protein in dot blot assays. Specifications. Form: Lyophilized powder.Read more e as a blocking agent. For instance, when using a monoclonal antibody raised against the amino acid sequence WSHPQFEK, the peptide is used for blocking the activity of Strep-tag II Antibody to ensure the specificity of the signal during Western blotting or immunohistochemistry.
Key Considerations for Researchers:
1. Tag Placement: The amino acid sequence can be placed at the N-terminus or C-terminus. However, always consult the specific sequencing data of your construct to ensure no secondary structures interfere with binding.
2. Elution Strategy: Because the Strep tag ii peptide sequence binds so specifically, competitive elution with a synthetic peptide is often the cleanest method to recover high-quality protein.
3. Experimental Control: Always keep a batch of the peptide on hand for It can be used for competitive elution ofStrep-tag®IIfusion proteins or as control protein in dot blot assays. Specifications. Form: Lyophilized powder.Read more blocking experiments. It is a reliable tool to verify that your antibody signal is truly binding to the target tag I May 27, 2017—The found peptid was a shortsequenceconsisting of only 8 amino acids (Trp-Ser-His-Pro-Gln-Phe-Glu-Lys) and was namedStrep-tag®II. Cite. 1 Read more I and not engaging in non-specific interactions.
In conclusion, the evolution from the original nine-residue peptide to the current WSHPQFEK standard has significantly streamlined the purification process. By focusing on the precise eight amino acid fusion tag structure, researchers can achieve consistent, reproducible results in their protein expression and purification workflows. Whether you are using it for purification or as a negative control, the reliability of this specific peptide remains unmatched in the field.