Peptide name : SP22

Source/Organism : Not found

Linear/Cyclic : Linear

Chirality : L

Peptide length: 22

C-terminal modification: Linear

N-terminal modification : Not found

Non-natural peptide information: None

Assay type : Tunnel assay

Assay time : 0.5-1h

Activity : Not found

Cell line : CHO

Cancer type : Ovarian cancer

Other activity : Not found

Amino acid composition bar chart :

Molecular mass : 2606.0408 Dalton

Aliphatic index : 0.268

Instability index : 123.55

Hydrophobicity (GRAVY) : -0.172

Isoelectric point : 6.4186

Charge (pH 7) : -0.8939

Aromaticity : 0.136

Molar extinction coefficient (cysteine, cystine): (16500, 16750)

Hydrophobic/hydrophilic ratio : 2.66666666

hydrophobic moment : -0.328

Missing amino acid : R,Q,T,I,E,K,F,Y,N,V

Most occurring amino acid : C

Most occurring amino acid frequency : 4

Least occurring amino acid : G

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.2, 0.2, 0.1)

SMILES Notation: CSCC[C@H](NC(=O)[C@@H]1CCCN1C(=O)[C@H](Cc1c[nH]cn1)NC(=O)[C@H](CCSC)NC(=O)[C@@H]1CCCN1C(=O)[C@H](CC(C)C)NC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CS)NC(=O)[C@H](C)NC(=O)[C@H](CO)NC(=O)[C@H](Cc1c[nH]cn1)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)CNC(=O)[C@H](Cc1c[nH]cn1)NC(=O)[C@H](CS)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@@H]1CCCN1C(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@H](Cc1c[nH]cn1)NC(=O)[C@H](CS)NC(=O)[C@H](C)N)C(=O)N[C@@H](CS)C(=O)O

1 : Li B, et al. Molecular mechanism of a novel CD59-binding peptide sp22 induced tumor cells apoptosis. J Cell Biochem. 2012; 113:3810-22. doi: 10.1002/jcb.24258

Paper title : Molecular mechanism of a novel CD59-binding peptide sp22 induced tumor cells apoptosis.

Doi : https://doi.org/10.1002/jcb.24258

Abstract : Some short peptides discovered by phage display are found to be able to inhibit cancer growth and induce cancer cell apoptosis. In this study, a novel cancer-targeting short peptide which was composed of 22 amino acids (ACHWPWCHGWHSACDLPMHPMC, abbreviated as sp22) and specifically bound to human CD59 was screened from a M13 phage display library so as to counteract tumor immune escape activity. The mechanism of exogenous sp22 peptide in inducing apoptosis of MCF-7 cells was investigated. The results suggested that sp22 could lower CD59 expression level, downregulate Bcl-2 expression, activate Fas and caspase-3, and finally increase apoptotic cell numbers of MCF-7 cells. However, sp22 had no obvious influence on normal human embryonic lung cells. In addition, the effects of endogenous sp22 gene on CD59 expression and NKM cell apoptosis were explored using the recombinant plasmid sp22-PIRES. It showed that sp22 gene was efficiently expressed in transfected NKM cells. Compared with normal NKM cells, NKM cells transfected with sp22 displayed reduced mRNA and protein expression levels of CD59, increased sensitivity to complement-mediated cytolysis, decreased cell survival ratio, changes of the expression of apoptosis associated proteins, increased number of apoptotic cells and the appearance of apoptotic morphology. The results suggested that sp22 protein could bind to CD59 and inhibit the expression of CD59. The cytolytic activity of complement on tumor cells strengthened and apoptosis signal was stepwise transferred which might be a potential way to kill tumor cells.