Compstatin 是一个 13 残基环肽,是补体系统 C3 的有效抑制剂,具有物种特异性。Compstatin 结合到狒狒的 C3,并对狒狒血液中的蛋白水解裂解具有抗性 (类似人类)。Compstatin 只抑制灵长类补体系统的激活。Compstatin 对补体经典途径和旁路途径的 IC50 值分别为 63 μM 和 12 μM。
生物活性 |
Compstatin, a 13-residue cyclic peptide, is a potent inhibitor of the complement system C3 with species specificity. Compstatin binds to baboon C3 and is resistant to proteolytic cleavage in baboon blood (similar to humans). Compstatin inhibits only the activation of primates’ complement system. Compstatin exhibits IC50 values of 63 μM and 12 μM for classical and alterative complement pathway, respectively[1][2][3][4].
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体外研究 (In Vitro) |
Compstatin exhibits an in vitro half-life in human blood of about2 hr[2]. In solution, compstatin forms a β-turn at residues Gln-5–Gly-8 with the disulfide bridge Cys-2–Cys12, residues Ile-1–Val-4, and Thr-13, forming a hydrophobic cluster[3].
MCE has not independently confirmed the accuracy of these methods. They are for reference only.
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体内研究 (In Vivo) |
Compstatin (21 mg/kg) produces complete inhibition when given as a combination of bolus injection and infusion. Compstatin completely inhibits in vivo heparin/protamine-induced complement activation without adverse effects on heart rate or systemic arterial, central venous, and pulmonary arterial pressures[1]. Compstatin is stable in baboon plasma for more than 24 h[1]. Pig xenografts survival is significantly longer in the Compstatin perfused group than in the control group[2].
MCE has not independently confirmed the accuracy of these methods. They are for reference only.
Animal Model: |
Juvenile baboons (P. Anubis) weighing 10.5-28.8 kg[1]. |
Dosage: |
50, 25 mg/kg 60 min after heparin and 2 min before protamine. |
Administration: |
A bolus injection. |
Result: |
Completely inhibited complement activation induced by heparin–protamine complexes. |
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分子量 |
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Formula |
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CAS 号 |
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Sequence |
Ile-Cys-Val-Val-Gln-Asp-Trp-Gly-His-His-Arg-Cys-Thr-NH2 (Disulfide bridge: Cys2-Cys12)
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Sequence Shortening |
ICVVQDWGHHRCT-NH2 (Disulfide bridge: Cys2-Cys12)
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中文名称 |
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运输条件 |
Room temperature in continental US; may vary elsewhere.
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储存方式 |
Powder |
-80deg;C |
2 years |
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-20deg;C |
1 year |
In solvent |
-80deg;C |
6 months |
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-20deg;C |
1 month |
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Solvent Solubility |
In Vitro:;
H2O
Peptide Solubility and Storage Guidelines:
1.;;Calculate the length of the peptide.
2.;;Calculate the overall charge of the entire peptide according to the following table:
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Contents |
Assign value |
Acidic amino acid |
Asp (D), Glu (E), and the C-terminal -COOH. |
-1 |
Basic amino acid |
Arg (R), Lys (K), His (H), and the N-terminal -NH2 |
+1 |
Neutral amino acid |
Gly (G), Ala (A), Leu (L), Ile (I), Val (V), Cys (C), Met (M), Thr (T), Ser (S), Phe (F), Tyr (Y), Trp (W), Pro (P), Asn (N), Gln (Q) |
0 |
3.;;Recommended solution:
Overall charge of peptide |
Details |
Negative (lt;0) |
1.;;Try to dissolve the peptide in water first. 2.;;If water fails, add NH4OH (lt;50 μL). 3.;;If the peptide still does not dissolve, add DMSO (50-100 μL) to solubilize the peptide. |
Positive (gt;0) |
1.;;Try to dissolve the peptide in water first. 2.;;If water fails, try dissolving the peptide in a 10%-30% acetic acid solution. 3.;;If the peptide still does not dissolve, try dissolving the peptide in a small amount of DMSO. |
Zero (=0) |
1.;;Try to dissolve the peptide in organic solvent (acetonitrile, methanol, etc.) first. 2.;;For very hydrophobic peptides, try dissolving the peptide in a small amount of DMSO, and then dilute the solution with water to the desired concentration. |
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参考文献 |
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[1]. Soulika AM, et al. Inhibition of heparin/protamine complex-induced complement activation by Compstatin in baboons. Clin Immunol. 2000 Sep;96(3):212-21.
[2]. Fiane AE, et al. Compstatin, a peptide inhibitor of C3, prolongs survival of ex vivo perfused pig xenografts. Xenotransplantation. 1999 Feb;6(1):52-65.
[3]. Bert J C Janssen, et al. Structure of compstatin in complex with complement component C3c reveals a new mechanism of complement inhibition. J Biol Chem. 2007 Oct 5;282(40):29241-7.
[4]. A Sahu, et al. Inhibition of human complement by a C3-binding peptide isolated from a phage-displayed random peptide library. J Immunol. 1996 Jul 15;157(2):884-91.
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