Cigarette smoking has severe health issue resulting in tremendous economic loss. Each year more than 480,000 people in the United States die due to chronic use of cigarettes. The total economic cost of smoking is more than $300 billion a year. Chronic smoking has been associated with many diseases some of which are attributed to conformation changes in proteins. Therefore, this study has investigated the effect of smoking on the conformational changes of a model protein lysozyme and alteration in its biological activity. The cigarette smoke was passed through citrate phosphate (CP) buffer (pH 4.4) which resulted into the formation of cigarette smoke extract (CSE) which is reported to simulate the presence of various chemicals found in such smoke. The CSE (10% to 50% v/v) was added to lysozyme solution (0.06% w/v) samples were taken specific time points. The samples were subjected to Fourier Transform Infrared (FTIR) and ultraviolet (UV) spectroscopic analysis for evaluation of changes in conformational integrity and biological enzyme activity of lysozyme, respectively. The results obtained indicated that CSE causes conformational stability perturbation in lysozyme which is associated with a corresponding decrease in its biological activity. However, this study did not include the effect of water insoluble components of cigarette smoke and the effect of CSE on long term exposure beyond the 72 hrs. Therefore, any future study should include the effect of long-term exposure of water soluble as well as insoluble components on conformation integrity and biological activity of proteins.
