Proteolytic compartmentalization and activity in the midgut of Andrallus spinidens Fabricius (Hemiptera: Pentatomidae)

Abstract

Digestive proteolytic activity in the alimentary canal of <em>Andrallus spinidens</em>, a potential biocontrol agent of lepidopteran larvae, was studied by considering enzyme compartmentalization and diversity. The alimentary canal of adults consists of a foregut, a four- sectioned midgut, namely V₁ to V₄ (ventriculus), and a hindgut. The optimal pH for general proteolytic activity was found to be at pH 8 with a small peak at pH 6. Results revealed that there are several specific proteases in the midgut of <em>A. spinidens</em>, including trypsin-like, chymotrypsin-like, and elastase as serine proteases, and cathepsins B, L and D as cysteine proteases, in addition to two exopeptidases of carboxy- and aminopetidases. Compartmentalization of digestive proteolytic activity showed that V₃ is the main area of proteolytic secretion for both general and specific proteases and that V₄ has the lowest enzymatic role, so that four out of the eight specific proteases found showed no activity in this section. The lowest and the highest proteolytic activity was found to be in the 1^st and 4^th nymphal instars, respectively. Using the specific inhibitors phenylmethylsulfonyl fluoride, Na-p-tosyl-L-lysine chloromethyl ketone, Ntosyl- L-phenylalanine chloromethyl ketone, L-trans-epoxysuccinyl-leucylamido-( 4-guanidino)-butane, cystatin, phenanthroline and ethylendiamidetetraacetic acid, we verified the presence of all specific proteases noted using both biochemical assays and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Our findings demonstrated that <em>A. spinidens</em> could utilize several caterpillars because of the presence of various of proteases in its midgut

A transcriptomic and proteomic atlas of expression in the Nezara viridula (Heteroptera: Pentatomidae) midgut suggests the compartmentalization of xenobiotic metabolism and nutrient digestion

“…N. viridula has a midgut that can be divided into four morphologically distinct sections along its anterior-posterior axis termed M1 (extreme anterior) to the extreme posterior (M4), which is separated from the first three anterior portions by a selective valve [6]. Some physiological roles have been assigned to these compartments; M3 has been implicated in nutrient digestion and the M4 region has long been known to harbor symbiotic bacteria which appear to be essential for growth [7][8][9]. However, neither the physiological roles or expression profiles of these gut compartments are fully understood.…”

Biochemical Characterization of Some Digestive Enzymes in the Midgut of Eristalis megacephala (Diptera: Syrphidae)

“…However, some properties of insect chymotrypsins contrast to those of vertebrate chymotrypsins, such as their instability at acid pH and their strong inhibition by soya bean trypsin inhibitor. Sorkhabi-Abdolmaleki et al (2013) demonstrated pH 9 and pH 9-10 for trypsin-like, chymotrypsin-like proteases of Andrallus spinidens, respectively. Sharma et al (1994) found a pH of 11 and 8 as the optimal values for activities of trypsin and chymotrypsin respectively in Tipula abdominalis larvae.…”

Dietary and phylogenetic correlates of digestive trypsin activity in insect pests

“…The high molecular mass trypsins found in some lepidopteran (Brito et al., ; Oliveira et al., ; Zibaee et al., ) and coleopteran species (Wagner et al., ; Hosseininaveh et al., ; Silva et al., ; Castro‐Guillén et al., ) have been suggested to result from oligomerisation, which interferes with binding of proteinaceous inhibitors present in their food. Also, the maintenance of high trypsin and proteinase activity within wide pH range in insects that use different isozymes and different mechanistic classes of proteinases, enables efficient digestion of proteins under variable gut conditions or simply reflects divergence in structure important for digestion of heterogeneous food proteins and circumventing proteinase inhibitors (Ortego et al., ; Zeng et al., ; Silva et al., ; Wright et al., ; Castro‐Guillén et al., ; Sorkhabi‐Abdolmaleki et al., ; Delkash‐Roudsari et al., ).…”

“…Although large differences in the major mechanistic classes of proteinases and proteinase structures have been recorded in phylogenetically distant species with similar feeding habits (Hughes & Vogler, ; Terra & Ferreira, ), it is reasonable to assume that the chemical composition of food as well as diet heterogeneity had a large impact on evolutionary diversification of proteinases. Specific food type may favor a shift to new proteinases (Murdock et al., ; Christeller et al., ; Johnson & Rabosky, ; Lopes et al., ) or the use of multiple mechanistic classes (Overney et al., ; Ortego et al., ; Silva et al., ; Hernández et al., ; Zhang & Brune, ; Sorkhabi‐Abdolmaleki et al., ) and multiple proteinase isozymes (Mazumdar‐Leighton & Broadway, ; Marshall et al., ; Spit et al., ) to digest proteins. Besides the evolutionary novelties in proteinase classes and structures, food composition may have both short‐ and long‐term influence on the regulation of proteinase activity.…”