CALP3 is a Ca2+-like peptide that is a potent Ca2+ channel blocker and activates the EF hand of Ca2+-binding proteins. CALP3 can mimic increased [Ca2+]i by regulating the activity of calmodulin (CaM), Ca2+ channels and pumps. CALP3 may be used to control apoptosis in diseases like AIDS or neuronal loss due to ischemia.

Physicochemical Properties

Molecular Formula	C₄₄H₆₈N₁₀O₉
Molecular Weight	881.07
Exact Mass	880.517
CAS #	261969-05-5
PubChem CID	10033623
Appearance	White to off-white solid powder
LogP	3.947
Hydrogen Bond Donor Count	11
Hydrogen Bond Acceptor Count	12
Rotatable Bond Count	29
Heavy Atom Count	63
Complexity	1470
Defined Atom Stereocenter Count	6
SMILES	CC(C)[C@@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC1=CC=CC=C1)C(=O)NCC(=O)N[C@@H](C(C)C)C(=O)NCC(=O)N[C@@H](CC2=CC=CC=C2)C(=O)N[C@@H](CCCCN)C(=O)O)N
InChi Key	OBMFGXCPBIYSPH-FFIZALLVSA-N
InChi Code	InChI=1S/C44H68N10O9/c1-27(2)37(47)42(60)51-31(19-11-13-21-45)40(58)53-33(23-29-15-7-5-8-16-29)39(57)48-26-36(56)54-38(28(3)4)43(61)49-25-35(55)50-34(24-30-17-9-6-10-18-30)41(59)52-32(44(62)63)20-12-14-22-46/h5-10,15-18,27-28,31-34,37-38H,11-14,19-26,45-47H2,1-4H3,(H,48,57)(H,49,61)(H,50,55)(H,51,60)(H,52,59)(H,53,58)(H,54,56)(H,62,63)/t31-,32-,33-,34-,37-,38-/m0/s1
Chemical Name	(2S)-6-amino-2-[[(2S)-2-[[2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S)-2-amino-3-methylbutanoyl]amino]hexanoyl]amino]-3-phenylpropanoyl]amino]acetyl]amino]-3-methylbutanoyl]amino]acetyl]amino]-3-phenylpropanoyl]amino]hexanoic acid
Synonyms	CALP-3; CALP 3
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro

Glutamate-induced substantial and sustained increase in [Ca2+]i is inhibited in a dose-dependent manner (IC50=37.25 μM) by CALP3 (50, 100, 150, 200 μM) in neuronal cells loaded with Fura-2 [1]. In cultured rat neocortical neurons, CALP3 (50, 100, 150, and 200 μM) reduces glutamate-induced cytotoxicity in a dose-dependent manner (IC50=50.97 μM). Apoptosis is dose-dependently inhibited by CALP3 (IC50 = 33.41 μM) [1]. Human T cell apoptosis mediated by HIV gp120 and SAg is inhibited by CALP3 (100 μM) [1]. Gossypol-induced necrosis is decreased and the percentage of viable cells is increased by CALP3 (100 μM; 15 min pretreatment) [2]. Fmoc-Asp(PEG-PS)-OA1 was the starting point for the synthesis of Cyclic-CALP3. Ca21 inflow was not inhibited by cyclic CALP3, and this peptide was used as a negative control. Glutamate's actions are not inhibited by cyclic CALP3 [1].

References

[1]. A new type of Ca(2+) channel blocker that targets Ca(2+) sensors and prevents Ca(2+)-mediated apoptosis. FASEB J. 2000 Jul;14(10):1297-306. [2]. BH3 mimetic-elicited Ca2+ signals in pancreatic acinar cells are dependent on Bax and can be reduced by Ca2+-like peptides. Cell Death Dis. 2017 Mar 2;8(3):e2640.

Solubility Data

Solubility (In Vitro)

DMSO : ~12.5 mg/mL (~14.19 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 1.25 mg/mL (1.42 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 12.5 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 1.25 mg/mL (1.42 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 12.5 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 1.25 mg/mL (1.42 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 12.5 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.1350 mL	5.6749 mL	11.3498 mL
	5 mM	0.2270 mL	1.1350 mL	2.2700 mL
	10 mM	0.1135 mL	0.5675 mL	1.1350 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.