TY - JOUR
T1 - Effects of the anti-bacterial peptide cecropin B and its analogs, cecropins B-1 and B-2, on liposomes, bacteria, and cancer cells
AU - Chen, Hueih Min
AU - Wang, Wei
AU - Smith, David
AU - Chan, Siu Chiu
PY - 1997/8/27
Y1 - 1997/8/27
N2 - Custom designed analogs of the natural anti-bacterial peptide cecropin B (CB) have been synthesized; cecropin B-1 (CB-1) was constructed by replacing the C-terminal segment (residues 26 to 35) with the N-terminal sequence of CB (positions 1 to 10 which include five lysine residues). The second analog, CB-2, is identical to CB-1 except for the insertion of a Gly-Pro residue pair between Pro-24 and Ala-25. These peptides were used to investigate their anti-liposome, anti-bacterial and anti-cancer activities. The strength of anti-liposome activity is reduced two- to three-fold when the analogs are used instead of natural CB based on DL50 analysis. Similarly, the potency of these analogs on certain bacteria is about two- to four-fold lower than those of CB based on LC measurements. In contrast, on leukemia cancer cells, the potency of CB-1 and CB-2 is about two- to three-fold greater than that of natural CB based on IC50 measurements. All CB, CB-1 and CB-2 peptides have comparable helix contents according to CD measurements. These results indicate that the designed cationic lytic peptides, having extra cationic residues, are less effective in breaking liposomes and killing bacteria but more effective in lysing cancer cells. The possible interpretations for these observations are discussed.
AB - Custom designed analogs of the natural anti-bacterial peptide cecropin B (CB) have been synthesized; cecropin B-1 (CB-1) was constructed by replacing the C-terminal segment (residues 26 to 35) with the N-terminal sequence of CB (positions 1 to 10 which include five lysine residues). The second analog, CB-2, is identical to CB-1 except for the insertion of a Gly-Pro residue pair between Pro-24 and Ala-25. These peptides were used to investigate their anti-liposome, anti-bacterial and anti-cancer activities. The strength of anti-liposome activity is reduced two- to three-fold when the analogs are used instead of natural CB based on DL50 analysis. Similarly, the potency of these analogs on certain bacteria is about two- to four-fold lower than those of CB based on LC measurements. In contrast, on leukemia cancer cells, the potency of CB-1 and CB-2 is about two- to three-fold greater than that of natural CB based on IC50 measurements. All CB, CB-1 and CB-2 peptides have comparable helix contents according to CD measurements. These results indicate that the designed cationic lytic peptides, having extra cationic residues, are less effective in breaking liposomes and killing bacteria but more effective in lysing cancer cells. The possible interpretations for these observations are discussed.
KW - Anti-bacteria
KW - Anti-cancer
KW - Cecropin
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U2 - 10.1016/S0304-4165(97)00024-X
DO - 10.1016/S0304-4165(97)00024-X
M3 - Article
C2 - 9305787
AN - SCOPUS:0030746525
SN - 0304-4165
VL - 1336
SP - 171
EP - 179
JO - Biochimica et Biophysica Acta - General Subjects
JF - Biochimica et Biophysica Acta - General Subjects
IS - 2
ER -