Peptide name : Brevinin-1RL1

Source/Organism : Not found

Linear/Cyclic : Linear

Chirality : L

Peptide length: 24

C-terminal modification: Linear

N-terminal modification : Not found

Non-natural peptide information: None

Assay type : Cell death assay

Assay time : 6 or 24h

Activity : IC50 : 5.44 ± 0.33 μM

Cell line : MDA-MB-231

Cancer type : Not specified

Other activity : Not found

Amino acid composition bar chart :

Molecular mass : 2713.3545 Dalton

Aliphatic index : 1.1

Instability index : 35.6792

Hydrophobicity (GRAVY) : 1.025

Isoelectric point : 10.106

Charge (pH 7) : 3.7383

Aromaticity : 0.166

Molar extinction coefficient (cysteine, cystine): (0, 125)

Hydrophobic/hydrophilic ratio : 3

hydrophobic moment : -0.033

Missing amino acid : W,H,Q,M,E,D,Y,N,V

Most occurring amino acid : F

Most occurring amino acid frequency : 4

Least occurring amino acid : G

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.3, 0.1, 0.4)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@@H]1CCCN1C(=O)[C@H](Cc1ccccc1)NC(=O)[C@@H](N)Cc1ccccc1)C(=O)N[C@@H](C)C(=O)NCC(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C)C(=O)N[C@@H](C)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CC(C)C)C(=O)N1CCC[C@H]1C(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CS)C(=O)N[C@@H](CO)C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CS)C(=O)O)[C@@H](C)O)[C@@H](C)CC)[C@@H](C)CC

1 : Kerkhofs M, et al. BIRD-2, a BH4-domain-targeting peptide of Bcl-2, provokes Bax/Bak-independent cell death in B-cell cancers through mitochondrial Ca2+-dependent mPTP opening. Cell Calcium. 2021; 94:102333. doi: 10.1016/j.ceca.2020.102333

Paper title : BIRD-2, a BH4-domain-targeting peptide of Bcl-2, provokes Bax/Bak-independent cell death in B-cell cancers through mitochondrial Ca2+-dependent mPTP opening.

Doi : https://doi.org/10.1016/j.ceca.2020.102333

Abstract : Anti-apoptotic Bcl-2 critically controls cell death by neutralizing pro-apoptotic Bcl-2-family members at the mitochondria. Bcl-2 proteins also act at the endoplasmic reticulum, the main intracellular Ca2+-storage organelle, where they inhibit IP₃ receptors (IP₃R) and prevent pro-apoptotic Ca2+-signaling events. IP₃R channels are targeted by the BH4 domain of Bcl-2. Some cancer types rely on the IP₃R-Bcl-2 interaction for survival. We previously developed a cell-permeable, BH4-domain-targeting peptide that can abrogate Bcl-2's inhibitory action on IP₃Rs, named Bcl-2 IP₃ receptor disrupter-2 (BIRD-2). This peptide kills several Bcl-2-dependent cancer cell types, including diffuse large B-cell lymphoma (DLBCL) and chronic lymphocytic leukaemia (CLL) cells, by eliciting intracellular Ca2+ signalling. However, the exact mechanisms by which these excessive Ca2+ signals triggered by BIRD-2 provoke cancer cell death remain elusive. Here, we demonstrate in DLBCL that although BIRD-2 activates caspase 3/7 and provokes cell death in a caspase-dependent manner, the cell death is independent of pro-apoptotic Bcl-2-family members, Bim, Bax and Bak. Instead, BIRD-2 provokes mitochondrial Ca2+ overload that is rapidly followed by opening of the mitochondrial permeability transition pore (mPTP). Inhibiting mitochondrial Ca2+ overload using Ru265, an inhibitor of the mitochondrial Ca2+ uniporter complex counteracts BIRD-2-induced cancer cell death. Finally, we validated our findings in primary CLL patient samples where BIRD-2 provoked mitochondrial Ca2+ overload and Ru265 counteracted BIRD-2-induced cell death. Overall, this work reveals the mechanisms by which BIRD-2 provokes cell death, which occurs via mitochondrial Ca2+ overload but acts independently of pro-apoptotic Bcl-2-family members.