Podisus nigrispinus (Dallas) is a common predator in agricultural and natural systems in Neotropical America. Its feeding strategy involves extra-oral digestion and to better understand this process its salivary glands were extracted and subjected to morphological and preliminary enzyme characterization. The salivary glands of P. nigrispinus are formed by a pair of main and accessory gland complexes. The main salivary glands are further divided into an anterior and a posterior lobe. The compartmentalization of the salivary gland complex is likely to be important for the production, activation and release of the digestive enzymes used in the extra-oral digestion of prey items. Proteases and lipase, important digestive enzymes involved in zoophagy, were detected in the salivary glands of P. nigrispinus. The prevailing trypsin-like protease activity was characterized by using the serine-protease substrate N-α-benzoyl-L-Arg-p-nitroanilidine (L-BApNA) and the trypsin inhibitors tosyl-L-lysine chloromethyl ketone (TLCK) and benzamidine. The KM value obtained for trypsin-like activity was 1.57 mm and the different peaks of optimum pH and temperature activity suggest the presence of multiple forms of this enzyme in P. nigrispinus. Detection of amylase activity in the salivary glands of this predator suggests its ability to digest starch and obtain nutrients from plants, which may have adaptative value under prey scarcity.

中文翻译：

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捕食性臭虫 Podisus nigrispinus（异翅目：蝽科）唾液腺的形态学和初步酶特征

黑棘鳅（达拉斯）是新热带美洲农业和自然系统中常见的捕食者。它的喂养策略涉及口腔外消化，为了更好地理解这一过程，提取了它的唾液腺并进行了形态学和初步酶表征。唾液腺黑棘由一对主腺体和副腺体复合体组成。主唾液腺进一步分为前叶和后叶。唾液腺复合体的区室化可能对于用于口外消化猎物的消化酶的产生、激活和释放很重要。在动物的唾液腺中检测到蛋白酶和脂肪酶，它们是参与动物自食性的重要消化酶黑棘。通过使用丝氨酸蛋白酶底物来表征普遍的胰蛋白酶样蛋白酶活性氮-α-苯甲酰基-L-Arg-对硝基苯胺 (L-BApNA) 和胰蛋白酶抑制剂甲苯磺酰基-L-赖氨酸氯甲基酮 (TLCK) 和苯甲脒。K中号获得的胰蛋白酶样活性值为 1.57 mm，最适 pH 值和温度活性的不同峰值表明该酶在体内存在多种形式。黑棘。对这种捕食者唾液腺中淀粉酶活性的检测表明它具有消化淀粉并从植物中获取营养的能力，这可能在猎物稀缺的情况下具有适应价值。