Pep-1

Product Name: Pep-1

Sequence One Letter Code: KETWWETWWTEWSQPKKKRKV

Sequence Three Letter Code: Lys-Glu-Thr-Trp-Trp-Glu-Thr-Trp-Trp-Thr-Glu-Trp-Ser-Gln-Pro-Lys-Lys-Lys-Arg-Lys-Val

Chemical Formula:C136H195N35O33

Molecular Weight: 2848.4

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: Cell Penetrating Peptides

Source / Species: Synthetic construct

Conjugation: Unconjugated

Code Nacres: NA.26

Application: Pep-1 is a synthetic cell-penetrating peptide engineered for efficient intracellular delivery of proteins and other macromolecules without causing membrane disruption. The peptide displays primary amphipathicity, consisting of a tryptophan-rich hydrophobic domain linked to a hydrophilic nuclear localization sequence derived from the SV40 large T-antigen, connected through a flexible spacer region. This unique structural design allows Pep-1 to form non-covalent complexes with cargo molecules and facilitate their direct translocation across the plasma membrane. As a result, Pep-1 is widely used in protein transduction research and intracellular delivery studies. The peptide is particularly valuable for transporting functional proteins, antibodies, or nucleic acids into living cells, supporting investigations in cell biology, molecular signaling, and the development of peptide-based delivery systems.

Current Research: Pep-1 is a synthetic cell-penetrating peptide (CPP) designed to facilitate efficient intracellular delivery of proteins and other macromolecules without disrupting cellular membranes. Unlike many delivery systems that rely on covalent conjugation or endosomal uptake pathways, Pep-1 enables the formation of non-covalent complexes with cargo molecules, allowing them to cross the plasma membrane and enter living cells while maintaining biological activity. Because of these properties, Pep-1 has become a widely used tool in protein transduction and intracellular delivery research. The peptide’s effectiveness stems from its carefully engineered amphipathic structure, which combines hydrophobic and hydrophilic domains connected by a flexible spacer region. This structural design allows Pep-1 to interact simultaneously with cellular membranes and cargo molecules, enabling efficient transport across the cell membrane. Structural Design of Pep-1 Pep-1 was specifically engineered to overcome limitations associated with early cell-penetrating peptides such as TAT and penetratin. Many earlier CPPs required chemical coupling of the peptide to the cargo molecule, which could interfere with protein folding or biological activity. Pep-1 addresses this limitation by enabling non-covalent complex formation with target macromolecules. The peptide contains three key structural elements: Tryptophan-rich hydrophobic domain Hydrophilic nuclear localization sequence (NLS) Flexible spacer region Together, these components create a primary amphipathic peptide structure that promotes efficient interaction with both cargo molecules and cellular membranes. Hydrophobic Domain and Membrane Interaction The N-terminal portion of Pep-1 contains a tryptophan-rich hydrophobic sequence. Tryptophan residues are particularly effective at interacting with lipid bilayers because their aromatic side chains can insert into membrane environments. This hydrophobic region allows Pep-1 to: Associate with cell membrane lipids Stabilize peptide–cargo complexes Promote membrane translocation By interacting with the lipid components of the plasma membrane, the hydrophobic domain plays a critical role in enabling cargo transport into cells. Hydrophilic Domain and Nuclear Localization Sequence The C-terminal portion of Pep-1 contains a hydrophilic nuclear localization sequence derived from the SV40 large T-antigen. Nuclear localization sequences are short peptide motifs recognized by cellular transport machinery responsible for nuclear import. In Pep-1, this region contributes to: Increased solubility in aqueous environments Electrostatic interactions with cargo molecules Potential support for intracellular targeting mechanisms The combination of hydrophobic and hydrophilic domains gives the peptide its amphipathic character, which is essential for efficient delivery. Role of the Flexible Spacer Separating the hydrophobic and hydrophilic domains is a flexible spacer sequence. This region improves structural adaptability and allows the peptide to adjust its conformation during complex formation and membrane interaction. The spacer provides several advantages: Enhances structural flexibility Reduces steric interference between peptide domains Improves cargo-binding capability This flexible design helps maintain the functional properties of both the peptide and the cargo molecules being transported. Non-Covalent Complex Formation One of the most distinctive features of Pep-1 is its ability to form stable non-covalent complexes with proteins and other macromolecules. Rather than chemically attaching to cargo molecules, Pep-1 associates with them through electrostatic and hydrophobic interactions. This approach offers several advantages: Avoids chemical modification of cargo proteins Preserves native protein structure and activity Simplifies preparation of delivery complexes Because the cargo molecules remain structurally intact, Pep-1 is particularly useful for delivering functional proteins into living cells. Applications in Protein Transduction Research Pep-1 is widely used in studies involving protein transduction, a technique that enables researchers to introduce functional proteins directly into cells. This approach allows scientists to analyze protein function without relying on gene expression systems. Typical experimental applications include delivery of: Enzymes and signaling proteins Antibodies or antibody fragments Transcription factors Fluorescent reporter proteins By delivering active proteins into cells, researchers can investigate cellular signaling pathways and protein function in real time. Use in Intracellular Delivery Systems Beyond protein transduction, Pep-1 has been explored as a versatile carrier for transporting a range of biological molecules into cells. Its ability to form non-covalent complexes makes it suitable for delivering: Peptides and proteins Nucleic acids Antibodies and antibody fragments Imaging probes and reporter molecules These capabilities make Pep-1 an important tool in cell biology, molecular signaling research, and experimental delivery system development. Studying Membrane Translocation Mechanisms Pep-1 is also frequently used in research investigating cellular uptake mechanisms and membrane translocation pathways. By examining how Pep-1–cargo complexes enter cells, scientists can better understand the molecular interactions involved in peptide-mediated delivery. Research in this area focuses on: Direct membrane penetration mechanisms Endocytic uptake pathways Intracellular trafficking of peptide–cargo complexes Efficiency of protein delivery into different cell types These studies contribute to broader efforts to design improved peptide-based delivery platforms. Conclusion Pep-1 is a synthetic amphipathic cell-penetrating peptide designed for efficient intracellular delivery of proteins and other macromolecules. Its unique structure—composed of a tryptophan-rich hydrophobic domain, a hydrophilic nuclear localization sequence derived from SV40 large T-antigen, and a flexible spacer region—enables the formation of non-covalent complexes with cargo molecules and promotes membrane translocation. Because Pep-1 can transport functional biomolecules into living cells without disrupting membrane integrity, it has become a widely used tool in protein transduction research, intracellular delivery studies, and investigations of cellular signaling mechanisms. Its versatility continues to support advances in cell biology, molecular research, and the development of peptide-based delivery technologies.