Ibarra-García Laura Elizabeth, Tovar-Ramírez Dariel, Rosas Carlos, Campa-Córdova Ángel Isidro, Mazón-Suástegui José Manuel
Centro de Investigaciones Biológicas del Noroeste, Av. Instituto Politécnico Nacional 195, 23096 La Paz, Baja California Sur, Mexico.
Unidad Multidisciplinaria de Docencia e Investigación, Facultad de Ciencias, Universidad Nacional Autónoma de México, Puerto de abrigo s/n, 97358 Sisal, Yucatán, Mexico.
Comp Biochem Physiol B Biochem Mol Biol. 2018 Jan;215:10-18. doi: 10.1016/j.cbpb.2017.10.001. Epub 2017 Oct 24.
Octopus bimaculoides is an important commercially fished species in the California Peninsula with aquaculture potential; however, to date limited information is available regarding its digestive physiology. The objective of this study was focused on biochemically characterizing the main enzymes involved in the digestion of O. bimaculoides. Optimum pH, temperature and thermostability were determined for amylases, lipases, trypsin and chymotrypsin; optimum pH and protease inhibitor effect were assessed for acidic and alkaline proteases, and the effect of divalent ions on trypsin and chymotrypsin activity was evaluated in enzymatic extracts from the digestive (DG) and salivary glands (SG) and crop gastric juices (GJ). High amylase activity was detected in GD and GJ whereas this activity is very low in other cephalopods. Salivary glands had the greatest activity in most of the enzyme groups, showing the importance of this organ in digestion. Optimum pH was different depending on the organ and enzyme analyzed. The optimum pH in DG was 3 showing the predominance of acidic proteases in the digestion process. All enzymes were resistant and stable at high temperatures in contrast with other marine species. Trypsin and chymotrypsin activity were highly incremented with the presence of Mg, Co, Cu and Zn in some tissues. The inhibitor assay showed the importance of serine proteases, metalloproteases and aspartic proteases in the digestive process of this species. This study is the first in assessing the main digestive enzymes of O. bimaculoides and in remarking the importance of other digestive enzyme groups besides proteases in octopuses.
双斑蛸是加利福尼亚半岛一种具有重要商业捕捞价值且有水产养殖潜力的物种；然而，迄今为止，关于其消化生理学的信息有限。本研究的目的是对参与双斑蛸消化的主要酶进行生化特性分析。测定了淀粉酶、脂肪酶、胰蛋白酶和糜蛋白酶的最适pH值、温度和热稳定性；评估了酸性和碱性蛋白酶的最适pH值和蛋白酶抑制剂的作用，并在消化腺（DG）、唾液腺（SG）和嗉囊胃液（GJ）的酶提取物中评估了二价离子对胰蛋白酶和糜蛋白酶活性的影响。在DG和GJ中检测到高淀粉酶活性，而在其他头足类动物中该活性非常低。唾液腺在大多数酶组中活性最高，表明该器官在消化过程中的重要性。根据所分析的器官和酶的不同，最适pH值也不同。DG中的最适pH值为3，表明酸性蛋白酶在消化过程中占主导地位。与其他海洋物种相比，所有酶在高温下都具有抗性且稳定。在某些组织中，Mg、Co、Cu和Zn的存在会使胰蛋白酶和糜蛋白酶的活性显著增加。抑制剂试验表明丝氨酸蛋白酶、金属蛋白酶和天冬氨酸蛋白酶在该物种消化过程中的重要性。本研究首次评估了双斑蛸的主要消化酶，并指出除蛋白酶外其他消化酶组在章鱼消化中的重要性。
