The overall subject of this study is LTPs from members of the Brassicaceae family. The project can be divided in two parts.
The first part revolves around LTP5 and LTP8 from A. thaliana, which have unusual LTP pIs of 11 and 5, respectively. 3D models of these two proteins were created by use of homology modeling, and calculation and visualization of their electrostatic potentials were performed. Significant differences were revealed from these, which suggested that these two proteins with very similar folds have different modes of action. LTP5 and LTP8 were attempted to be produced in different strains of P. pastoris. Low amounts of putative LTP5 were detected in concentrated supernatant from one expression study, and was found to have antimicrobial activity against B. subtilis. In general, accumulation of LTP5 and LTP8 was not detectable following the expression studies conducted under different conditions, and characterizations of these proteins were therefore not possible within the time frame.
In the second part, selective protocols for extraction and isolation of putative LTPs from cabbage were developed. The developed protocols were considered well-suitable for isolation of LTPs, but needs improvements in terms of yield and through-put. It was concluded that 3 distinct members of the LTP family 1 with different tissue specificities were identified
and partly isolated by use of the protocols. Lipid transfer activity assays were performed to verify that the proteins were true LTPs, however, the results remained inconclusive. No antimicrobial activity on four tested microbes could be detected with low concentrations of the putative LTP-fractions.