Product Details

CasNo： /

Molecular Formula： C33H57N11O9

Product Overview

Selank is a synthetic short peptide consisting of seven amino acid residues. Its amino acid sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, with the one-letter sequence TKPRPGP.

Structurally, Selank is associated with the Tuftsin peptide sequence and contains an additional Pro-Gly-Pro segment, forming a complete heptapeptide structure.

Due to its clearly defined sequence and compact molecular architecture, Selank is commonly studied in the context of short-peptide structure, sequence design, conformational analysis, and structure–function relationship research.

This page provides scientific information about the molecular structure, sequence characteristics, and analytical characterization approaches of Selank.

---

Molecular and Structural Information

Item	Information
Name	Selank
Amino Acid Sequence	Thr-Lys-Pro-Arg-Pro-Gly-Pro
One-Letter Sequence	TKPRPGP
Peptide Length	7 amino acids
Peptide Type	Synthetic heptapeptide / Tuftsin-derived short peptide
Molecular Formula	C33H57N11O9
Molecular Weight	Approx. 751.87 g/mol
Structural Features	Short peptide containing Pro-Gly-Pro sequence
Research Context	Short-peptide structure, sequence design, conformational analysis, and structure–function studies

---

Structural Features

Defined Heptapeptide Framework

Selank consists of seven amino acid residues arranged as Thr-Lys-Pro-Arg-Pro-Gly-Pro.

Although the peptide chain is relatively short, each amino acid contributes different structural characteristics:

• Thr contains a hydroxyl-containing side chain and contributes polarity;
• Lys and Arg contain basic side chains that influence charge distribution;
• Pro has a cyclic structure that affects local peptide conformation;
• Gly provides structural flexibility due to its small side chain.

The combination of these residues forms the structural basis of Selank.

---

Relationship to Tuftsin-Derived Sequences

The N-terminal region of Selank is related to the Tuftsin sequence.

Tuftsin is a naturally occurring tetrapeptide with the sequence:

Thr-Lys-Pro-Arg

Selank extends this sequence by adding a Pro-Gly-Pro segment:

Thr-Lys-Pro-Arg-Pro-Gly-Pro

This sequence extension makes Selank a useful model for studying peptide fragment combination, sequence modification, and structural changes in short synthetic peptides.

It is important to distinguish Selank from Tuftsin, as they are different molecular structures with different peptide lengths and complete sequences.

---

Pro-Gly-Pro Sequence Characteristics

The C-terminal region of Selank contains the Pro-Gly-Pro sequence.

Proline has a cyclic side chain that can influence local peptide arrangement, while glycine has a small side chain and generally provides greater conformational flexibility.

The presence of Pro-Gly-Pro gives Selank structural characteristics different from the original Tuftsin tetrapeptide and represents an important region when studying peptide conformation and sequence extension effects.

---

Short-Peptide Structure Research

Because Selank contains only seven amino acids, it provides a relatively clear model for studying how individual residues influence peptide properties.

Research topics may include:

• Amino acid sequence arrangement
• Charge distribution
• Local peptide conformation
• The influence of Pro and Gly residues on flexibility
• Relationship between peptide length and structure
• Effects of amino acid substitutions

Comparative studies of sequence variants can help clarify the relationship between peptide composition and molecular characteristics.

---

Sequence–Structure Relationship Studies

Selank can be used as a model peptide for investigating sequence–structure relationships.

Researchers may compare structural variations involving:

• Amino acid substitutions
• Sequence extension or shortening
• N-terminal or C-terminal modifications
• Changes in the Pro-Gly-Pro region
• Different molecular forms

These comparisons help evaluate how sequence composition, side-chain properties, and structural modifications influence peptide behavior.

For short peptides, even a single residue change may affect charge distribution, molecular conformation, and analytical characteristics, making accurate sequence confirmation important.

---

Different Molecular Forms

In scientific references, Selank may appear in different molecular forms, such as free peptide or salt forms.

Although these forms share the same core heptapeptide sequence, they may differ in:

• Molecular composition
• Theoretical molecular weight
• Ionic state
• Analytical behavior
• Chromatographic characteristics

When comparing data from different sources, the following information should be considered together:

• Complete amino acid sequence
• Molecular formula
• Molecular weight
• Salt form
• Analytical data

The peptide name alone is not always sufficient to determine the exact molecular form.

---

Analytical and Structural Characterization

Selank can be characterized using established analytical methods commonly applied to peptide research.

Common approaches include:

• High-performance liquid chromatography (HPLC)
• Mass spectrometry (MS)
• LC-MS analysis
• Molecular-weight verification
• Amino acid sequence analysis
• Peptide mapping
• Related-component analysis

HPLC can provide information about chromatographic behavior and major components, while MS and LC-MS can support molecular-weight and identity confirmation.

For different molecular forms or salt states, analytical results should be interpreted according to the specific molecular composition.

---

Frequently Asked Questions

Why may the reported molecular weight of Selank differ between sources?

Differences may result from molecular form, salt state, or database recording methods. Molecular formula, theoretical molecular weight, and specific structural information should be reviewed together.

Is Selank the same molecule as Tuftsin?

No. Tuftsin is a tetrapeptide with the sequence Thr-Lys-Pro-Arg, while Selank contains an additional Pro-Gly-Pro segment, resulting in a seven-amino-acid peptide.

Why is the peptide name alone not enough to confirm Selank identity?

Different references may describe different molecular forms or salt states. Complete sequence, molecular weight, and analytical data provide more reliable identification.

What is the role of the Pro-Gly-Pro segment in Selank?

The Pro-Gly-Pro sequence is a structural feature that distinguishes Selank from Tuftsin and contributes to the peptide’s conformational characteristics.

Which analytical methods are commonly used to characterize Selank?

Common methods include HPLC, MS, LC-MS, molecular-weight verification, and peptide sequence analysis.