CONACyT-Centro de Investigaciones Biológicas del Noroeste, México City, México.
Centro de Investigaciones Biológicas del Noroeste, México City, México.
PLoS One. 2020 Sep 18;15(9):e0239413. doi: 10.1371/journal.pone.0239413. eCollection 2020.
In arthropods, the cleavage of specific proteins by peptidases has pivotal roles in multiple physiological processes including oogenesis, immunity, nutrition, and parasitic infection. These enzymes are also key players in the larval development, and well-described triggers of molting and metamorphosis. In this work the peptidase complement throughout the larvae development of Penaeus vannamei was quantified at the transcript and activity level using qPCR and fluorogenic substrates designed to be hydrolyzed by class-specific peptidases respectively, providing a detailed identification of the proteolytic repertoire in P. vannamei larvae. Significant changes in the peptidase activity profile were observed. During the lecithotrophic naupliar instars, the dominant peptidase activity and expression derive from cysteine peptidases, suggesting that enzymes of this class hydrolyze the protein components of yolk as the primary amino acid source. At the first feeding instar, zoea, dominant serine peptidase activity was found where trypsin activity is particularly high, supporting previous observations that during zoea the breakdown of food protein is primarily enzymatic. At decapodid stages the peptidase expression and activity is more diverse indicating that a multienzyme network achieves food digestion. Our results suggest that proteolytic enzymes fulfill specific functions during P. vannamei larval development.
在节肢动物中，肽酶对特定蛋白质的裂解在包括卵发生、免疫、营养和寄生虫感染在内的多种生理过程中起着关键作用。这些酶也是幼虫发育的关键因素，也是蜕皮和变态的成熟触发因素。在这项工作中，使用 qPCR 和设计用于被特定类别的肽酶水解的荧光底物，在转录和活性水平上定量了凡纳滨对虾幼虫发育过程中的肽酶组成，详细鉴定了凡纳滨对虾幼虫的蛋白水解酶谱。观察到肽酶活性谱的显著变化。在无节幼体阶段，优势的肽酶活性和表达来源于半胱氨酸肽酶，表明该类酶水解卵黄的蛋白质成分作为主要的氨基酸来源。在第一期摄食幼体阶段，幼体，发现优势的丝氨酸肽酶活性，其中胰蛋白酶活性特别高，这支持了先前的观察结果，即在幼体阶段，食物蛋白的分解主要是酶促的。在十足幼体阶段，肽酶的表达和活性更加多样化，表明多酶网络实现了食物消化。我们的结果表明，蛋白酶在凡纳滨对虾幼虫发育过程中发挥特定的功能。
