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The two peptide lantibiotic lacticin 3147 is effective in bacteriocin induced lysis. Girbe Buist. Department of Dairy Science and Technology, Instituto del Frío (CSIC), Ciudad Universitaria, Madrid, Spain Carmen Martínez-Cuesta Teresa Requena Elisabet Herranz Carmen Peláez
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The two peptide lantibiotic lacticin 3147 is effective in bacteriocin induced lysis Girbe Buist Department of Dairy Science and Technology, Instituto del Frío (CSIC), Ciudad Universitaria, Madrid, Spain Carmen Martínez-Cuesta Teresa Requena Elisabet Herranz Carmen Peláez Department of Biochemistry, University of Oslo, NorwayHavard Hauge Jon Nissen-Meyer Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Jan Kok
Bacteriocincharacteristics • produced by L. lactis IFPL105, isolated from Spanish raw goats’ milk • heat stable • broad spectrum of inhibitory activity • hydrolyzed by chymotrypsin, proteinase K and pancreatin • resistant to trypsin and pepsin • genes for immunity and production located on 46 kb plasmid pBAC105
0.3 14 0.3 14 12 12 10 10 0.2 0.2 60 8 8 10 3 x Activity (BU ml-1) 10 3 x Activity (BU ml-1) A A 280 280 6 6 40 2-Propanol (%) 0.1 0.1 4 4 20 2 2 0 0 0 0 0 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 Elution Volume (ml) Elution Volume (ml) a b Reverse-phasechromatography • peptide is 3322 Da • peptide is 2848 Da • complementary action needed for activity
N-termini blocked • peptide cleft by chymotrypsin • Edman: Ile-(Ser)-Thr-Asn-Thr-(Glu)-Pro • homologous to a peptide of lacticin 3147 Amino acid and nucleotide sequence • ltnA1 encodes a peptide of 59 aa • ltnA2 encodes a peptide of 62 aa • ‘double-Gly’ type leader peptides
Amino acidcomposition • LtnA1 and LtnA2 are post-translational modified • Ser > D-Ala conversion shown and lanthionine present
~ 13 Kb ltn operon • gene organization in pBAC105 and pMRC01 are identical
Lacticin 3147 • produced by L. lactis DPC3147 isolated from Irish kefir grain • PMF promotes the interaction with membrane • pores are selective for K+ ions and inorganic phosphate • dissipation of the membrane potential > hydrolysis of ATP > collapse of the pH gradient > cell death • induces cell lysis • lytic response is strain dependent
10 Growth (OD600) 1 0.1 0 2 4 6 Time (h) 0 hours 3 hours % lysis 1.0 109 1.0 108 14.9 (1.5) 6.0 105 8.7 103 25.7 (0.8) 0 hours 3 hours % lysis 3.3 109 1.0 108 32.5 (2.3) 5.3 107 4.8 103 51.3 (1.2) 0 hours 3 hours % lysis 6.8 108 1.0 108 15.6 (1.3) 5.4 108 3.0 105 74.5 (3.7) 10 10 Growth (OD600) 1 Growth (OD600) 1 0.1 0.1 0 2 4 6 0 2 4 6 Time (h) Time (h) Lb. rhamnosus JCL1211 L. lactis IFPL359 Lb. casei IFPL731 Lacticin 3147induced lysis • loss of viability not concurrent with cell lysis • addition of Co2+ or SDS reduces lysis
5 4 MG1363acmA 3 OD[600nm] 2 MG1363 1 0 0 30 60 90 120 150 180 Time in hours AcmA: responsible for autolysis
10 0.035 0.030 0.025 0.020 600 1 OD MG1363 Units of PepX / ml 0.015 0.010 0.005 0.1 0 0 2 4 6 8 10 Time (h) Involvement of AcmA in lacticin induced lysis
10 0.035 0.030 0.025 Bac 0.020 600 1 OD MG1363 Units of PepX / ml 0.015 MG1363 (+Bac) 0.010 0.005 0.1 0 0 2 4 6 8 10 Time (h) Involvement of AcmA in lacticin induced lysis
10 0.035 0.030 0.025 Bac 0.020 600 1 OD MG1363 Units of PepX / ml 0.015 MG1363 (+Bac) 0.010 MG1363acmA (+Bac) 0.005 0.1 0 0 2 4 6 8 10 Time (h) Involvement of AcmA in lacticin induced lysis • reduction of viability identical • AcmA responsible for lacticin 3147 induced lysis
Lacticin 3147 does not activate AcmA • similar results obtained when using Nisin or a mixture of lactococcins A, B, and M Cell wall degradation
Depletion of cellular energy causes an imbalance in the control of the action of the autolysin, resulting in cell wall degradation and, thus, cell lysis. Conclusion