TLR3 receptor recognizes stranded RNA, which is characteriostic for replication stage of several viruses. It is activated only through binding of dsRNA longer than 21 base pairs. We have discovered the existence of additional RNA binding site at N-terminus. TLR3 dimerization is thus requires binding of RNA to both binding sites , which defines recognition of only longer segments of dsRNA.
COBISS.SI-ID: 3954714
We constructed a molecular model of the three-dimensional structure of MD-2, which is a key protein for recognition of bacterial endotoxin. The model was prepared by the use of sequence threading where we identified the allergen Der p2 as a protein having a similar folding pattern as MD-2. By means of point mutations of MD-2 and with peptide fragments of MD-2 we showed the importance of two groups of basic amino acid residues for the activation of LPS signalling in cell culture. The obtained model explains the results of native mutants and systematic mutagenesis of MD-2 very well.
COBISS.SI-ID: 3073306
Knowledge of the spatial structure of antimicrobial peptides is of major importance for understanding the mechanism of their activity and for rational improvements. By the use of spectroscopic techniques, foremost NMR, we determined the structure of an antimicrobial peptide based on the sequence of human lactoferrin in solution, as well as in complex with LPS and different types of lipid environment. We found that the peptide, upon binding to LPS or other lipids, folded into a defined conformation, depending on the type of the environment.
COBISS.SI-ID: 3635994
The protein MD-2 plays a key role in detection and signalling of bacterial endotoxin. In the HapMap database we found two mutations in MD-2. We found that mutation G56R perceivably diminished the LPS responsiveness of transfected HEK293 cells. The most interesting result is the fact that MD-2 with the mentioned mutation cannot activate cells that do not express their own MD-2, but depended on the MD-2 provided by other cells.
COBISS.SI-ID: 3905562