Variations in Amino Acid Composition of Antisense Peptide-Phosphorodiamidate Morpholino Oligomer Affect Potency against Escherichia coli In Vitro and In Vivo ▿
| Autor: | Brett L. Mellbye, Bruce L. Geller, Susan E. Puckett, Lucas D. Tilley, Patrick L. Iversen |
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| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Morpholino
Arginine Morpholines Molecular Sequence Data Colony Count Microbial Peptide Phenylalanine Microbial Sensitivity Tests Biology Peritonitis Morpholinos chemistry.chemical_compound Mice Structure-Activity Relationship Lipid biosynthesis Escherichia coli Animals Pharmacology (medical) Amino Acid Sequence Amino Acids Mechanisms of Action: Physiological Effects Escherichia coli Infections Pharmacology chemistry.chemical_classification Ornithine Oligonucleotides Antisense Amino acid Anti-Bacterial Agents Infectious Diseases chemistry Biochemistry Sequence motif |
| Popis: | The potency of antisense peptide-phosphorodiamidate morpholino oligomers (PPMOs) was improved by varying the peptide composition. An antisense phosphorodiamidate morpholino oligomer (PMO) complementary to the mRNA of the essential gene acpP (which encodes the acyl carrier protein required for lipid biosynthesis) in Escherichia coli was conjugated to the 5′ ends of various cationic membrane-penetrating peptides. Each peptide had one of three repeating sequence motifs: C-N-N (motif 1), C-N (motif 2), or C-N-C (motif 3), where C is a cationic residue and N is a nonpolar residue. Variations in the cationic residues included arginine, lysine, and ornithine (O). Variations in the nonpolar residues included phenylalanine, valine, β-alanine (B), and 6-aminohexanoic acid (X). The MICs of the PPMOs varied from 0.625 to >80 μM (about 3 to 480 μg/ml). Three of the most potent were the (RX) 6 B-, (RXR) 4 XB-, and (RFR) 4 XB-AcpP PMOs, which were further tested in mice infected with E. coli . The (RXR) 4 XB-AcpP PMO was the most potent of the three conjugates tested in mice. The administration of 30 μg (1.5 mg/kg of body weight) (RXR) 4 XB-AcpP PMO at 15 min postinfection reduced CFU/ml in blood by 10 2 to 10 3 within 2 to 12 h compared to the numbers in water-treated controls. All mice treated with 30 μg/dose of (RXR) 4 XB-AcpP PMO survived infection, whereas all water-treated mice died 12 h postinfection. The reduction in CFU/ml in blood was proportional to the dose of PPMO from 30 to 300 μg/ml. In summary, the C-N-C motif was more effective than the other two motifs, arginine was more effective than lysine or ornithine, phenylalanine was more effective than 6-aminohexanoic acid in vitro but not necessarily in vivo, and (RXR) 4 XB-AcpP PMO reduced bacterial infection and promoted survival at clinically relevant doses. |
| Databáze: | OpenAIRE |
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