Medicina Molecular e Genética

Effect of Amitriptyline an Antidepressant Drug on Structural and Functional Properties of Brain Cystatin

Abstract

Fakhra Amin and Bilqees Bano

Cystatins are the thiol proteinases inhibitors of prime physiologic importance. They are ubiquitously present in mammalian body. They prevent unwanted proteolysis and play important role in several diseases. Regulation of cysteine proteinases and their inhibitors are of utmost importance in diseases like Alzheimer, amlyoid angiopathy and other neurodegenerative disease. Proteinase anti-proteinase imbalance accelerates disease progression. Amitriptylin an antidepressant helps to relieve depression and pain. It is often used to manage nerve pain resulting from cancer treatment. Such injury to nerves causes a burning, tingling sensation. This medication, usually given at bedtime, helps patients to sleep better

In this paper interaction of brain cystatin (BC) with Amytriptyline (AMY) has been studied by UV absorption and fluorescence spectroscopy. In the present study, the effect of drug has been studied to explore AMY induced changes in functional and structural integrity of the cystatin. The fluorescence quenching data is indicative of complex formation between the protein and drug which confirmed the binding of Amytriptyline with brain cystatin. Stern-Volmer analysis of Amytriptyline binding with brain cystatin indicates the presence of static component in the quenching mechanism. The thermodynamic parameters ΔG° (Free energy change) -36.966 KJ/mol indicated that both hydrogen bonds and hydrophobic interactions played a major role in the binding of AMY with BC. Binding investigations give in this work, gives significant information about the conformational changes in cystatin due interaction with the drug.