초록
<P><B>Abstract</B></P> <P>β-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 β-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 β -galactosidase as estimated by using SDS-PAGE was 42 kDa. Kinetic parameters K<SUB>m</SUB> and V<SUB>max</SUB> 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 β-galactosidase activity were found to be 6, 40 °C, respectively. The present study is aimed to purification, characterization and <I>in vitro</I> efficacy assessment in breast cancer cell line. The β-galactosidase isolated from <I>Aspergillus terreus</I> was found to be effective in the proliferation of MCF-7 breast cancer cells <I>in vitro</I>. The present study is aimed to purification and characterization of enzyme to assess <I>in vitro</I> efficacy of β-galactosidase on MCF-7 cell line to delineate its therapeutic efficacy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> β-galactosidase catalyzes hydrolysis and transglycosylation reaction. </LI> <LI> β-galactosidase from <I>Aspergillus terreus</I> was purified with maximum enzyme activity 80.6 U/mg, protein and the purification fold 10.78 with 28.26% yield. </LI> <LI> Characterization of enzyme activity was done by determining the optimum pH 6.0, temperature 40 °C. </LI> <LI> β-galactosidase shows an indicator of the switch mechanism used by cells to enter senescence. </LI> <LI> The treatment of MCF-7cell line with β-galactosidase resulted in appreciable inhibition of cell growth. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>