Expression, Purification, and Characterization of a Novel Hybrid Peptide with Potent Antibacterial Activity.
Wei. Xubiao X; Wu. Rujuan R; Zhang. Lulu L; Ahmad. Baseer B; Si. Dayong D; Zhang. Rijun R
Key Findings
- The hybrid peptide (C‑L) is more antibacterial and less hemolytic than the original peptides alone.
- It can be produced in E. coli with a high yield (about 89 mg/L of fusion protein, 17.5 mg/L of pure peptide).
- C‑L remains active up to 80 °C, across pH 5‑10, and retains >50 % activity after treatment with pepsin, trypsin, or proteinase K.
Practical Outcomes
- While the peptide isn’t ready for human or animal use yet, the study shows a feasible method for DIY‑bio labs to make a potent antimicrobial. The stability data suggest it could be formulated into a shelf‑stable product, but extensive safety and dosing studies are still needed before anyone should try it.
Summary
Researchers made a new hybrid peptide that combines parts of two natural antimicrobial proteins (cecropin A and LL‑37). This hybrid kills bacteria better than either piece alone and hurts red blood cells less. They figured out a way to produce it in large amounts using common lab bacteria and showed it stays active under a wide range of temperatures, pH levels, and even after exposure to some digestive enzymes.
Abstract
The hybrid peptide cecropin A (1⁻8)⁻LL37 (17⁻30) (C⁻L), derived from the sequence of cecropin A (C) and LL-37 (L), showed significantly increased antibacterial activity and minimized hemolytic activity than C and L alone. To obtain high-level production of C⁻L, the deoxyribonucleic acid sequence encoding C⁻L with preferred codons was cloned into pET-SUMO to construct a fusion expression vector, and overexpressed in <i>Escherichia coli</i> (<i>E. coli</i>) BL21 (DE3). The maximum fusion protein (92% purity) was obtained with the yield of 89.14 mg/L fermentation culture after purification with Ni-NTA Sepharose column. The hybrid C⁻L was cleaved from the fusion protein by SUMO-protease, and 17.54 mg/L pure active C⁻L was obtained. Furthermore, the purified C⁻L showed identical antibacterial and hemolytic activity to synthesized C⁻L. Stability analysis results exhibited that the activity of C⁻L changed little below 80 °C for 20 min, but when the temperature exceeded 80 °C, a significant decrease was observed. Varying the pH from 5.0 to 10.0 did not appear to influence the activity of C⁻L, however, pH below 4.0 decreased the antibacterial activity of C⁻L rapidly. Under the challenge of several proteases (pepsin, trypsin, and proteinase K), the functional activity of C⁻L was maintained over 50%. In summary, this study not only supplied an effective approach for high-level production of hybrid peptide C⁻L, but paved the way for its further exploration in controlling infectious diseases of farm animals or even humans.
Study Information
pubmed
2018
2018-06-20T00:00:00.000Z
10.3390/molecules23061491
36
39