Tests for ampicillin resistance given by protein added to mediumPiotr
Results of growth from previous day
OmpA variant ("hunter") | "Prey" variant | Growth with prey | Growth without prey |
OmpA-alpha | His+Z+omega | + | + |
OmpA-alpha | His+Z+alpha | + | + |
OmpA-A-alpha | His+Z+omega | + | - |
Ompa-A-omega | His+Z+alpha | + | - |
OmpA-omega | His+Z+alpha | + | - |
Ompa-Z-alpha | His+Z+omega | + | - |
OmpA_Adelta_alpha | His+Z+omega | + | - |
OmpA_Adelta_omega | His+Z+alpha | + | - |
OmpA_omega_Adelta | His+Z+alpha | + | - |
OmpA-omega-A-alpha | no | + | + |
- Isolation of plasmids from above cultures.
- Control
digest of isolated plasmids with BamHI and SacI.
- Gel electrophoresis - all constructs apart from pACYC177+OmpA_alpha were successfully recovered.
Conclusions:
- Almost none of tested constructs give resistance to ampicillin without prey protein added to culture medium.
- Interaction between hunter and prey is not necessary to make cells ampicillin resistant (OmpA_alpha and OmpA_omega grow with prey).
- pACYC177+OmpA_alpha culture may be contaminated with antibiotic-resistant bacteria, alpha doesn't need interaction of A and Z proteins to bind to omega - maybe we must give bacteria less prey.
Cloning of protein A DNA to GeneArt plasmidAntoni
- Colony PCR on colonies from plates with transformations pGeneart+A.
Primers used:
AP+NotI and AL+SacI.
- Gel electrophoresis.
- Confirmed transformant colonies inoculated to liquid LB with ampicillin.
Michał K.
- Isolation of plasmids from cultures inoculated on previous day.
- Control
digest of isolated plasmids with FastBamHI and FastAcc65I (Fast Digest buffer).
- Gel electrophoresis - no proper clones found (Fig. 1.).
Fig. 1. Control Acc65I/BamHI digests of isolated plasmids
1. Marker
2-3. digested plasmids pACYC177+OmpA_A_omega+alpha
4-5. digested plasmids pACYC177+OmpA_Z_omega+alpha
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