Secondary Structural Conformation of Lysozyme at Lipid Membrane Interface Using Circular Dichroism Spectroscopy
Secondary Structural Conformation of Lysozyme at Lipid Membrane Interface Using Circular Dichroism Spectroscopy
Abdul Majid1*, Farah Naz1, Nasrullah Laghari1, Sanaullah Abbasi1, Sham Lal2 and Safdar Ujjan3
ABSTRACT
This study employs the Circular Dichroism Spectroscopy (CDS) to unfold the possible changes in secondary structural conformation of lysozymes in different pH, temperature and lipid bilayer interfaces. The choice of solvents for the proteins functionality is remained a challenge for biochemical applications, hence there is always a need to understand the effects of solvents on secondary structural conformation. Biophysical investigations about the changes in secondary structure conformation of lysozymes were performed with CDS using them in water and buffer. Membrane bilayer mimics were prepared from dimyristoylphosphatidylcholine (DMPC) through rehydration method. CDS identified that secondary structure was maintained in saline phosphate buffer (PBS) pH (6.4, 7.4 and 8.0), similar to that of water. Temperature based experiments depicted the resistance due to changes in the secondary structural conformation up to 50 °C, however such resistance was reversible after the cooling to 20 °C. In both solvents (PBS and water) lysozyme was predominantly folded to α-helical conformation. At 50 °C, helices were altered to turns. However, in presence of dimyristoylphosphatidylcholine (DMPC) lipid bilayer interfaces, lysozyme adopted β-sheet conformation. This study proposed that hydrophobic groves of lysozyme could be a key in changes of structural conformation while interacting with lipid membrane bilayers. Such protein membrane interactions would facilitate the membrane perturbation. Here, we confirmed the supporting evidence that lysozyme could perturb the lipid bilayer and conforming the sheet structure. Overall, this research suggests that lysozyme could be a tool for designing the novel drug delivery vehicles along its already published potential application.
To share on other social networks, click on any share button. What are these?
