Surface-exposed amino acids of eosinophil cationic protein play a critical role in the inhibition of mammalian cell proliferation
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Eosinophil cationic protein (ECP) is a ribonuclease secreted from activated eosinophils that may cause tissue injure as a result of eosinophilic inflammation. ECP possesses bactericidal, antiviral and helminthotoxic activity and inhibits mammalian cell growth. The mechanism by which ECP exerts its toxicity is not known but it has been related to the ability of the protein to destabilise lipid bilayers. We have assessed the involvement of some cationic and aromatic surface exposed residues of ECP in the inhibition of proliferation of mammalian cell lines. We have constructed ECP mutants for the selected residues and assessed their ability to prevent cell growth. Trp10 and Trp35 together with the adjacent stacking residue are critical for the damaging effect of ECP on mammalian cell lines. These residues are also crucial for the membrane disruption activity of ECP. Other exposed aromatic residues packed against arginines (Arg75-Phe76 and Arg121-Tyr122) and specific cationic amino acids (Arg101and Arg104) of ECP play a secondary role in the cell growth inhibition. This may be related to the ability of the protein to bind carbohydrates such as those found on the surface of mammalian cells.
Keywordscell proliferation inhibition cytotoxicity eosinophils eosinophil cationic protein ribonuclease
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- 18.Domachowske JB, Dyer KD, Adams AG, Leto TL, Rosenberg HF: Eosinophil cationic protein/RNase 3 is another RNase A-family ribonuclease with direct antiviral activity. Nucleic Acids Res 24: 3507–3513, 1998Google Scholar
- 30.Futami J, Maeda T, Kitazoe M, Nukui E, Tada H, Seno M, Kosaka M, Yamada H: Preparation of potent cytotoxic ribonucleases by cationization: enhanced cellular uptake and decreased interaction with ribonuclease inhibitor by chemical modification of carboxyl groups. Biochemistry 40: 7518–7524, 2001PubMedGoogle Scholar
- 36.Ricard-Blum S, Feraud O, Lortat-Jacob H, Rencurosi A, Fukai N, Dkhissi F, Vittet D, Imberty A, Olsen BR, Van Der Rest M: Characterization of endostatin binding to heparin and heparan sulphate by surface plasmon resonance and molecular modeling: role of divalent cations. J Biol Chem 279: 2927–2936, 2004CrossRefPubMedGoogle Scholar
- 37.Ogawa Y, Iwama M, Ohgi K, Tsuji T, Irie M, Itagaki T, Kobayashi H, Inokuchi N: Effect of replacing the aspartic acid/glutamic acid residues of bullfrog sialic acid binding lectin with asparagine/glutamine and arginine on the inhibition of cell proliferation in murine leukemia P388 cells. Biol Pharm Bull 25: 722–727, 2002CrossRefPubMedGoogle Scholar