Digestive enzymes of large cabbage white butterfly,Pieris brassicaeL. (Lepidoptera: Pieridae) from developmental and site of activity perspectives

Abstract

Investigation of digestive enzymes in the alimentary tract of insects is very important for knowledge on physiology of nutrition. The overall results of this study showed the presence of the majority of digestive enzymes including α-amylase, α-and β-glucosidase and galactosidase, lipases and proteases in the midgut of Pieris brassicae. It was found that the fourth and fifth instar larvae had the highest enzymatic activity, but the obvious differences were found in the cases of sites of enzyme activity known as soluble and membrane-bound fractions. The highest enzymatic activities in the soluble fractions were found in cases of α-amylase, lipases and proteinases such as trypsin-like, chymotrypsin-like and elastase. In contrast, glycosidases and exopeptidases (amino and carboxypeptidases) demonstrated the highest enzymatic activity in the membrane-bound fractions. However, no enzymatic activity was observed on cysteine protease as a type of proteinases. By using line regression, parameter β (slope) showed larval dependency on enzymes along with developmental and feeding processes. It was found that α-glucosidase had the highest slope and the membrane-bound fraction of general proteases had the lowest, showing high and low dependencies of larvae to α-glucosidase and exopeptidases, respectively, in addition to second priority on β-glucosidase and α-amylase. Optimal pHs of soluble and membrane-bound α-amylase were found at 9 while all assayed glycosidases had the highest activity at pH 8 for both fractions. Soluble fraction of lipase had the highest enzymatic activity at pH 8 in comparison with membrane-bound fraction at pH 10. The soluble fraction showed the highest proteolytic activity at pH 9, while the highest proteolytic activity was observed at pH 8 in the case of the membrane-bound one.

Revisiting Rubisco as a Protein Substrate for Insect Midgut Proteases

“…Larval midgut proteases of Helicoverpa armigera (a noctuid polyphagous pest in Asia and Australia), Pieris brassicae (a Pierid specialist pest of Crucifers), and Antheraea assamensis (a beneficial saturniid silkworm that preferentially feeds on Lauraceae family) were evaluated using recombinant RBCL, casein and native Rubisco as substrates, in the presence of protease inhibitors and a reducing agent, dithiothreitol (DTT). Midgut serine proteinases have already been reported from these insects using various synthetic substrates (Johnston et al., ; Christeller et al., ; Kumar, ; Saikia et al., ; Zibaee, ). Like other Lepidoptera, these insects are also known to show differential expression of digestive proteases in response to the nature of ingested food (Gatehouse et al., ; Kumar, ; Saikia et al., ).…”

Ambient temperature‐mediated enzymic activities and intestinal microflora in Lymantria dispar larvae

“…Both amylase (AMS) and trehalase (THL) are important carbohydrases in all insects, which catalyze hydrolysis of carbohydrates (Hill & Orchard, 2005). They catalyze the hydrolysis α-D-(1,4)-glucan linkages and 1,1-glycosidic bond into glycogen and other related carbohydrates for absorption via epithelial cells (Zibaee, 2012). Lipase (LPS) that can catalyze the hydrolysis of fatty acid ester bonds is widely distributed in all insects (Grillo, Majerowicz, & Gondim, 2007).…”

A DIGESTIVE LIPASE OF Pieris brassicae L. (LEPIDOPTERA: PIERIDAE): PURIFICATION, CHARACTERIZATION, AND HOST PLANTS EFFECTS

“…Ions can affect enzymatic activity via activation of electrophiles and nucleophiles by taking and releasing electrons, and increasing the efficiency of the enzyme-substrate complex as well as the stability of enzyme (Zibaee, 2012). In the present study, 5 mM Mg 2+ and Na + had the most significant effects on increasing and decreasing, respectively, the purified lipase activity from P. brassicae, both in vitro and in vivo.…”

“…However, the effects of tetrahydrolipstatin on the growth, development, and survival of larvae of Epiphyas postvittana (Walker; Tortricidae, Lepidoptera) were reported (Markwick et al, 2011). In our previous study, we described a digestive lipase of P. brassicae as a soluble enzyme and had the highest activity in fourth instar larvae (Zibaee, 2012). Hence, the objectives of this study were (i) purification of the digestive lipase by column chromatography; (ii) characterization of the purified lipase by pH, temperature, inhibitors, and molecular mass; and (iii) effect of three host plants and their extracted inhibitor on digestive lipase activity.…”