Peptide name : PTP-7S

Source/Organism : PTP-7

Linear/Cyclic : Linear

Chirality : L

Peptide length: 16

C-terminal modification: Linear

N-terminal modification : Free

Non-natural peptide information:

Assay type : MTT assay

Assay time : 24-h

Activity : 55 - 60% cell viability at 75 µM

Cell line : HeLa

Cancer type : Cervical Cancer

Other activity : Anticancer

Amino acid composition bar chart :

Molecular mass : 1793.1105 Dalton

Aliphatic index : 1.343

Instability index : 0.35

Hydrophobicity (GRAVY) : 0.5437

Isoelectric point : 6.2407

Charge (pH 7) : -0.1624

Aromaticity : 12.5

Molar extinction coefficient (cysteine, cystine): (0, 0)

Hydrophobic/hydrophilic ratio : 1.6667

hydrophobic moment : 1.5096

Missing amino acid : C,D,H,I,M,P,Q,R,T,V,W,Y

Most occurring amino acid : L

Most occurring amino acid frequency : 5

Least occurring amino acid : N

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (68., 18., 43.)

SMILES Notation: CC(C)C[C@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CO)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](C)NC(=O)[C@H](CCCCN)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](C)NC(=O)CNC(=O)[C@H](CC(C)C)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CC(N)=O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@@H](N)CCC(=O)O)C(=O)O

1 : Sun F, et al. High-Resolution Insights into the Stepwise Self-Assembly of Nanofiber from Bioactive Peptides. J Phys Chem B. 2017; 121:7421-7430. doi: 10.1021/acs.jpcb.7b03626

Paper title : High-Resolution Insights into the Stepwise Self-Assembly of Nanofiber from Bioactive Peptides.

Doi : https://doi.org/10.1021/acs.jpcb.7b03626

Abstract : Peptide self-assembly has a profound biological significance since self-assembled bioactive peptides are gifted with improved bioactivity as well as life-span. In this study, peptide self-assembly was investigated using a therapeutic peptide, PTP-7S (EENFLGALFKALSKLL). Combining experiments of atomic force microscopy (AFM), circular dichroism (CD), and 8-anilino-1-naphthalenesulfonic acid (ANS) fluorescence spectra, PTP-7S showed the α-helical structure and was found self-assembling into nanofibers in solution. Relying on the coarse-grained (CG) dynamic simulations, the self-assembling of PTP-7S was revealed as a stepwise process that peptide monomers first clustered into peptide-assembling units (PUs) with charged surface, and then the PUs integrated together to construct nanofibril aggregates. Different roles of the nonbonded driving forces did play in the two phases: the hydrophobic force and electrostatic interaction acted as the predominant motivations in the formation of PUs and nanofiber, respectively. Moreover, the electrostatic interaction helped to guide the longitudinal growth of peptide nanofibers. A sequence principle is proposed for peptide self-assembling in aqueous solution: a balance of the counter charges and sufficient hydrophobicity degree. The self-assembled PTP-7S displayed good anticancer activity, proteases resistance, and sustained drug-release, showing a great potential for clinical application. This study reveals the molecular mechanism in explaining PTP-7S self-assembly and it is beneficial for future innovation of the self-assembled bioactive peptides.