Application of the GW module for the immobilization of the red fluorescent protein RFP on peptidoglycan from lactic acid bacteria <i>Lactococcus lactis</i> and <i>Lactobacillus acidophilus</i>

Introduction. Peptidoglycans from lactic acid bacteria are a safe platform for surface display systems of heterologous proteins for medical purposes. The binding of target proteins to peptidoglycans can occur with the participation of the GW protein module. Aim: to study the ability of GW module to bind proteins to peptidoglycan derived from lactic acid bacteria. Materials and methods: The fused protein GW-RFP was obtained with the help of genetically engineering methods. The protein was isolated and purified. Lactic acid bacteria peptidoglycans were isolated and used in the binding reaction with the GW-RFP protein. To monitor the reaction progress, light and fluorescence microscopy and polyacrylamide gel electrophoresis electrophoresis (PAGE) were used. Results: Methods for isolation and purification of peptidoglycans from Lactococcus lactis and Lactobacillus acidophilus have been developed. The recombinant GW-RFP protein consisting of the red fluorescent protein RFP and the GW module the AltA protein of Staphylococcus aureus has been cloned and expressed in Escherichia coli. It has been shown that the GW-RFP protein binds to the peptidoglycans from L. lactis and L. acidophilus in the amount of 24.9 ± 3.7 μg protein/100 μg (w/w) peptidoglycan from L. lactis and 21.3 ± 3.3 μg protein/100 μg (w/w) peptidoglycan from L. acidophilus. The GW-RFP protein can be removed from the peptidoglycans using a 0.5 M NaCl solution. Conclusion: The GW module can be used for protein immobilization on the peptidoglycan from both lactococci and lactobacilli.