Purification and characterization of anti-tubercular and anticancer protein from Staphylococcus hominis strain MANF2: In silico structural and functional insight of peptide

The present context was investigated to purify and characterize anti-tubercular as well as anticancer protein from fermented food associated Staphylococcus hominis strain MANF2. Initially, the anti-tubercular potency of strain MANF2 was assessed against Mycobacterium tuberculosis H37Rv using luciferase reporter phase assay which revealed pronounced relative light unit (RLU) reduction of 92.5 ± 1.2%. The anticancer property of strain MANF2 was demonstrated against lung cancer (A549) and colon cancer (HT-29) cell lines using MTT assay which showed reduced viabilities. Anti-tubercular activities of the purified protein were observed to be increased significantly (P < 0.05) ranging from 34.6 ± 0.3 to 71.4 ± 0.4% of RLU reduction. Likewise, the purified protein showed significantly (P < 0.05) reduced viabilities of A549 and HT-29 cancer cells with IC(50) values of 46.6 and 48.9 µg/mL, respectively. The nominal mass of the purified protein was found to be 7712.3 Da as obtained from MALDI-TOF MS/MS spectrum. The protein showed the sequence homology with 1–336 amino acids of Glyceraldehyde-3-phosphate dehydrogenase from Staphylococcus sp., thus, categorizing as a new class of Glyceraldehyde-3-phosphate dehydrogenase-like protein. The amino acid sequence of the most abundant peptide (m/z = 1922.12) in the purified protein was obtained as ‘KAIGLVIPEIDGKLDGGAQRV’ and it was identified as peptide NMANF2. In silico tools predicted significant stereo-chemical, physiochemical, and functional characteristics of peptide NMANF2. In a nutshell, protein purified from strain MANF2 can certainly be used as an ideal therapeutic agent against tuberculosis and cancer (lung and colon).