Characterization of β-galactosidase in the Crude Plant Extract of <i>Artemisia judaica</i> L. in Presence and Absence of Some Heavy Metals

Abstract

β-galactosidase (EC 3.2.1.23) is important in the formation of a medicinal plant Artemisia judaica (al-ba'atharan) aroma. The crude plant extracts of Artemisia judaica were used to characterize the enzyme in the term of pH, temperature, enzyme kinetic and effects of some heavy metals on its activity. The enzyme activity was measured by its ability to hydrolyze the substrate 2-nitrophenyl β-D-galactopyranoside (ONPG). The enzyme activity was reached maximum at 50°C and at pH 6.0. The K m and V max values of the enzyme were 3.6 mM and 1.67 µmol/min, respectively. Uncompetitive inhibition was observed in presence of Hg +2 , Fe +3 and Zn +2 for the enzyme β-galactosidase in the crude extract through the decrease in the K m and V max values. Pb +2 and Cu +2 were found to act as a noncompetitive inhibitors on the enzyme β-galactosidase in the crude extract due to increase in the K m values and decrease in V max values. The study showed that Hg +2 was the most potent inhibitor while Cu +2 exhibited the least inhibition degree on β-galactosidase activity in the Artemisia judaica. These finding indicated that the enzyme β-galactosidase in the crude leaves extract of Artemisia judaica can be used in industrial and medical applications.

Defensive forwards: stress-responsive proteins in cell walls of crop plants

“…In rice, β-galactosidase gene responds to ABA and water-stress [43] and germin-like proteins are associated with salt stress [44]. In other plants, β-galactosidase was found to be related to abiotic stress, especially heavy metals [45]; glycine-rich proteins [46,47] and cell wall invertase (copper stress, [48]) are stress-induced. Stress upregulates the expression of expansins and xyloglucan-modifying enzymes that can remodel the wall under abiotic stress [49].…”

Plant DNases are potent therapeutic agents against Echis carinatus venom‐induced tissue necrosis in mice

“…All the medicinal plants showed DNase activity and among them, T. tricuspidata showed potent DNase activity (Figure ). There are several scientific reports on plant hydrolytic enzymes, such as proteases, invertases, β‐galactosidase, and DNases . However, the role of plant hydrolytic enzymes, in particular, DNases in the neutralization of venom‐induced local wound has not been addressed.…”

“…There are several scientific reports on plant hydrolytic enzymes, such as proteases, invertases, β-galactosidase, and DNases. [39][40][41][42] However, the role of plant hydrolytic enzymes, in particular, DNases in the neutralization of venom-induced local wound has not been addressed. Interestingly, T. tricuspidata DNase reversed E. carinatus venom-induced tissue necrosis and retained normal tail tissue morphology (Figure 3).…”

Digging for Stress-Responsive Cell Wall Proteins for Developing Stress-Resistant Maize

“…In rice, β-galactosidase gene responds to ABA and water-stress ( Mundy and Chua, 1988 ) and germin-like proteins are associated with salt stress ( Banerjee et al, 2017 ). In other plants, β-galactosidase is found to be related to heavy metals ( Atrooz and Abukhalil, 2016 ); glycine-rich proteins ( Ringli et al, 2001 ; Mangeon et al, 2010 ) and cell wall invertase (copper stress, Xu et al, 2017 ) are stress-induced. Stress upregulates the expression of expansins and xyloglucan-modifying enzymes that can remodel the wall under abiotic stresses ( Tenhaken, 2014 ).…”