Antibacterial activity of Trichosanthes cucumerina seed lectin and study of its structural stability by fluorescence spectroscopy
By: Md. Golam Kibria, Md. Rezaul Karim, Imtiaj Hasan, A.K.M. Asaduzzaman, Md. Belal Uddin, Syed Rashel Kabir
Key Words: Fluorescence spectroscopy; bacterial agglutination; bacterial growth inhibition.
Int. J. Biosci. 9(6), 187-192, December 2016.
A Trichosanthes cucumerina seed lectin (TCSL) was purified previously that showed potent inhibitory effects against Ehrlich ascites carcinoma (EAC) cells in vivo in mice. In the present study, the lectin was treated with guanidine-HCl for 2 and 4h in the presence and absence of Ca2+ and changes in the tryptophan fluorescence shift were monitored by fluorescence spectroscopy. It was found that the lectin stability was increased in the presence of Ca2+. Although the denaturant changed the environment of tryptophan residue, it did not affect the binding sites of TCSL as red blood cells became agglutinated after the treatment with EDTA. Besides the agglutination of three pathogenic bacterial species, the lectin also partially inhibited the growth of Salmonella enteritidis and Staphylococcus aureus.