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09:27
Functional Complementation Analysis (FCA): A Laboratory Exercise Designed and Implemented to Supplement the Teaching of Biochemical Pathways
Published on: June 24, 2016
Extensive post-translational modification, including serine to D-alanine conversion, in the two-component
1Dairy Products Research Centre, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland.
The Journal of Biological Chemistry
|December 23, 1999
Summary
Lacticin 3147, a potent antimicrobial, is a novel two-component lantibiotic. Its D-alanine content and extensive post-translational modifications contribute to its broad-spectrum activity against Gram-positive bacteria.
Area of Science:
- Microbiology
- Biochemistry
- Molecular Biology
Background:
- Lacticin 3147 is a two-component bacteriocin from Lactococcus lactis subspecies lactis DPC3147.
- Bacteriocins are ribosomally synthesized antimicrobial peptides with diverse structures and functions.
Purpose of the Study:
- To biochemically characterize the two peptide components of Lacticin 3147.
- To elucidate the post-translational modifications contributing to Lacticin 3147's antimicrobial activity.
Main Methods:
- Isolation and purification of LtnA1 and LtnA2 peptides.
- Conventional amino acid analysis.
- Chiral phase gas chromatography coupled with mass spectrometry.
- Amino acid sequence analysis.
Main Results:
- LtnA1 (30 amino acids, 3,322 Da) and LtnA2 (29 amino acids, 2,847 Da) were isolated.
- Both peptides contain lanthionine and an excess of alanine.
- D-alanine residues were detected in both peptides, arising from post-translational modification of serine.
Conclusions:
- Lacticin 3147 is a novel lantibiotic containing D-alanine.
- Extensive post-translational modifications are key to its potent antimicrobial activity.
- This modification may explain its efficacy against various Gram-positive bacteria.
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