Biochemical characterisation of chlorophyllase from leaves of selected Prunus species--a comparative study.

Abstract

Despite senescence-induced chlorophyll depletion in plants has been widely studied, the enzymatic background of this physiologically regulated process still remains highly unclear. The purpose of this study was to determine selected biochemical properties of partially purified fractions of chlorophyllase (Chlase, chlorophyll chlorophyllido-hydrolase, EC 3.1.1.14) from leaves of three Prunus species: bird cherry (Prunus padus L.), European plum (Prunus domestica L.), and sour cherry (Prunus cerasus L.). Secondarily, this report was aimed at comparing seasonal dynamics of Chlase activity and chlorophyll a (Chl a) content within investigated plant systems. Molecular weight of native Chlase F1 has been estimated at 90 kDa (bird cherry) and approximately 100 kDa (European plum and sour cherry), whereas molecular mass of Chlase F2 varied from 35 kDa (European plum) to 60 kDa (sour cherry). Furthermore, enzyme fractions possessed similar optimal pH values ranging from 7.6 to 8.0. It was found that among a broad panel of tested metal ions, Hg(+2), Fe(+2), and Cu(+2) cations showed the most pronounced inhibitory effect on the activity of Chlase. In contrast, the presence of Mg(+2) ions influenced a subtle stimulation of the enzymatic activity. Importantly, although Chlase activity was negatively correlated with the amount of Chl a in leaves of examined Prunus species, detailed comparative analyses revealed an incidental decrement of enzymatic activity in early or moderately senescing leaves. It provides evidence that foliar Chlase is not the only enzyme involved in autumnal chlorophyll breakdown and further in-depth studies elucidating this catabolic process are required.

Effect of Ph and Calcium Chloride on the Thermal Inactivation Kinetics and Stability of Chlorophyllase in Mulberry Leaves

“…Kelly, 2016; Ge et al, 2022; Chattopadhyay et al, 2023).The results of this study were consistent with the ndings for green tea leaves(Okazawa et al, 2006;Sytykiewicz et al, 2013;Ozkan and Ersus Bilek, 2015) Okazawa et al(2006). reported that a pH level of 7.5 was optimal for Chlase extraction from green tea leaves.…”

“…reported that a pH level of 7.5 was optimal for Chlase extraction from green tea leaves. Similarly,Sytykiewicz et al(2013) found that the optimum Chlase pH in wheat seedlings ranged from 7.0 to 8.0. Ozkan and Ersus Bilek (2015) reported that the Chlase activity in spinach was highest at pH 7.0.…”

“…The Chlase was extracted using a method described by Sytykiewicz et al (2013) with some modi cations. Here, 50 g mulberry leaves were mixed with 200 mL phosphate buffer (0.1 M, pH 7.0, containing 0.2% Triton X-100, 30 g/L polyvinylpyrrolidone, 1 mM phenylmethylsulfonyl uoride, and 5 mM Cysteine), pulped for 1 min at room temperature using a juice extractor, and extracted for 1 h at 4 ℃.…”

“…Several studies have focused on extracting, purifying, and characterizing the Chlase in tea leaves (Li et al, 2011), mature leaves (Pothinuch and Tongchitpakdee, 2019), and spinach (Huang et al, 2010), showing that its catalytic properties depend on the raw materials or reaction system (Shara et al, 2018). A reaction temperature ranging from 65 ℃ to 82 ℃ and a slightly alkaline environment (pH 7.5 ~ 8.0) are optimal for increasing Chlase activity (Shara et al, 2018), while metal ions also play an important role (Li et al, 2011;Sytykiewicz et al, 2013). The temperature, pH, and other factors affect the enzyme activity and change the thermal resistance and stability during processing and storage (Liu et al, 2013;Gundogdu et al, 2011;Kubo et al, 2018).…”