%0 Journal Article %A Roy, Samir K. %A Dey, Susanta K. %A Raha, Syamal K. %A Chakrabarty, S. L. %T Purification and properties of an extracellular endoglucanase from Myceliophthora thermophila D-14 (ATCC 48104) %D 1990 %J Microbiology, %V 136 %N 10 %P 1967-1971 %@ 1465-2080 %R https://doi.org/10.1099/00221287-136-10-1967 %I Microbiology Society, %X An extracellular endoglucanase (1,4-β-glucanohydrolase, EC 3.2.1.4) produced by Myceliophthora thermophila D-14 (ATCC 48104) has been purified to homogeneity by ammonium sulphate precipitation and two consecutive ion-exchange chromatographic steps on DEAE-Sephadex A-50 columns. The enzyme was purified 13·8-fold and was homogeneous by analytical PAGE and SDS-PAGE. It has a high apparent M r, of about 100000. The pH and temperature optima for its activity were 4·8 and 65°C respectively. The K m of the purified enzyme for CMC (sodium salt) was 3 mg ml−1. The enzyme displayed low activity toward salicin and p-nitrophenyl β-d-glucoside. The activity was enhanced in the presence of Na+, K+ and Ca2+ but effectively inhibited by Hg2+, Fe2+, Mg2+, Cu2+ and NH4 +. Inhibition studies indicated that the enzyme may be a metalloprotein and/or that it requires metal lons for its optimum activity. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-136-10-1967