Mycobacterium tuberculosis secretory antigen ES-31 (ES-31)

Mycobacterium tuberculosis secretory antigen ES-31 is a 31 kDa glycoprotein actively secreted by the pathogen during its growth and infection stages. This antigen exhibits multifunctional enzymatic activities, specifically acting as both a chymotrypsin-like serine protease and a lipase, which are critical for the survival and multiplication of the bacteria within host macrophages (Wankhade et al., 2011; Harinath et al., 2014). ES-31 facilitates the invasion of host cells and supports nutrient acquisition through the hydrolysis of proteins and lipids. In clinical practice, it serves as a valuable diagnostic biomarker for both pulmonary and extra-pulmonary tuberculosis, utilized in assays like the SEVA TB ELISA to monitor infection and treatment efficacy (Upadhye et al., 2007). Experimental evidence suggests that its enzymatic functions can be significantly inhibited by antitubercular drugs such as Isoniazid and certain protease or lipase inhibitors like Orlistat and Ritonavir, highlighting its potential as a therapeutic target for disrupting the mycobacterial life cycle (Reddy et al., 2012). Development of specific inhibitors against ES-31 could offer new avenues for treating drug-resistant tuberculosis.

Other names

SEVA TB ES-3131 kDa excretory-secretory antigenMetallo-serine protease ES-31Excretory-secretory antigen 31Tubercular antigen ES-3131 kDa mycobacterial antigen

Inhibition of the dual enzymatic activity (serine protease and lipase) essential for mycobacterial metabolism, macrophage invasion, and intracellular survival within the host.