Purification and characterization of ß-galactosidase from newly isolated Aspergillus terreus (KUBCF1306) and evaluating its efficacy on breast cancer cell line (MCF-7).

ß-galactosidases (EC 3.2.1.23) are able to catalyze two different types of reactions, namely hydrolysis and transgalactosylation. It is a lysosomal exoglycosidase involved in the catabolism of glycoconjugates by sequential release of ß-linked terminal galactosyl residues. It has profound significance in cancer cell senescence. It can be derived from microbial sources including bacteria, yeasts, and filamentous fungi. The enzyme was purified from the crude enzyme using ammonium sulfate precipitation, dialysis, ion exchange chromatography using DEAE cellulose, fast protein liquid chromatography and high performance liquid chromatography. The enzyme was purified with 10.78 -fold with specific activity of 62 U/mg of protein and yield of 28.26%. Molecular weight of ß -galactosidase as estimated by using SDS-PAGE was 42 kDa. Kinetic parameters Km and Vmax for purified enzyme were 0.48 and 0.96 respectively. Further the characterization and kinetic studies of purified enzyme were carried out. The optimum pH and temperature for maximum ß-galactosidase activity were found to be 6, 40 °C, respectively. The present study is aimed to purification, characterization and in vitro efficacy assessment in breast cancer cell line. The ß-galactosidase isolated from Aspergillus terreus was found to be effective in the proliferation of MCF-7 breast cancer cells in vitro. The present study is aimed to purification and characterization of enzyme to assess in vitro efficacy of ß-galactosidase on MCF-7 cell line to delineate its therapeutic efficacy.

Quinazoline derivative from indigenous isolate, Nocardiopsis alba inhibits human telomerase enzyme.

AIM: Aim of this study was isolation and screening of various secondary metabolites produced by indigenous isolates of soil Actinomycetes for human telomerase inhibitory activity. METHODS AND RESULTS: Extracellular extract from culture suspension of various soil Actinomycetes species were tested for telomerase inhibitory activity. The organism which produced telomerase inhibitor was identified by 16S rRNA gene sequencing. The active fraction was purified by HPLC and analysed by GC-MS to identify the compound. In GC-MS analysis, the active principle was identified as 3-[4'-(2″-chlorophenyl)-2'-thiazolyl]-2,4-dioxo-1,2,3,4-tetrahydro quinazoline. The G-quadruplex stabilizing ability of the compound was checked by molecular docking and simulation experiments with G-quadruplex model (PDB ID-1L1H). The selective binding ability of the compound with G-quadruplex over Dickerson-Drew dodecamer DNA structures showed that the compound possess high selectivity towards G-quadruplex. CONCLUSIONS: Quinazoline derivative isolated from an indigenous strain of Nocardiopsis alba inhibited telomerase. Molecular docking and simulation studies predicted that this compound is a strong stabilizer of G-quadruplex conformation. It also showed a preferable binding to G-quadruplex DNA over normal DNA duplex. SIGNIFICANCE AND IMPACT OF THE STUDY: This particular compound can be suggested as a suitable compound for developing a future anticancer drug. The selectivity towards G-quadruplex over normal DNA duplex gives a clue that it is likely to show lower cytotoxicity in normal cells.