Digestion in Arachnida and the control of proteolytic activity
| Grant number: | 07/01706-3 |
| Support type: | Scholarships in Brazil - Master |
| Effective date (Start): | September 01, 2008 |
| Effective date (End): | June 30, 2010 |
| Field of knowledge: | Biological Sciences - Biochemistry - Enzymology |
| Principal Investigator: | Adriana Rios Lopes |
| Grantee: | Rodrigo Moreti da Silva |
| Home Institution: | Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil |
Abstract Arthropoda (Insecta, Crustacea and Arachnida) are the most abundant form of animal life on the planet, with perhaps a million species. The digestive system of this group of animals is one of the most important contact surfaces with environment and many of the adaptations, which allowed the occupation of diverse niches, occurred in the digestive system. Characterization of Arthropoda digestion showed that different Arthropoda groups present particularities in both, morphological and molecular aspects of digestion. The knowledge about Arthropoda digestion is large to Insect and Crustacea. However, there is a lack of data about Arachnida digestion, mainly the molecular aspects of digestion, making impossible comparative and evolutive studies between Arachnida and the other Arthropoda digestion. Polimers digestion, carbohydrates or proteins, occurs in three phases, initial, intermediate and final digestion. The remove of monosaccharides is usually related to final digestion. Alpha-fucosidases (EC 3.2.1.51) are glycosyl-hydrolases (GH, family 29), which catalyses the hydrolysis of glycosidic linkages (alpha 1,2, alfa 1,3, alpha 1,4 e alpha 1,6) present in glycoconjugates (carbohydrates, glycoproteins, glycolipids and glycosaminoglycans) between a fucose and other molecules. In general, these enzymes also hydrolyze synthetic substrates as methylumbelliferyl-alpha-L-fucoside. This enzyme has been studied in other organisms, mainly molluscs and bacterias, besides human alpha-fucosidase. The enzymatic synthesis of fucooligosaccharides is an alternative to chemical methods One alternative for the synthesis of fucosyl glycans is to exploit the transfer activity of alpha-L-fucosidases. Despite their involvement in critical biological roles, fucooligosaccharides remain relatively inaccessible to scientific and pharmaceutical research due to the difficulties inherent in their synthesis. The transglycosylation activity of alpha-L-fucosidases is highly variable depending on the origin of the enzymes, which makes fundamental the study of new models. Glycoproteins which presents fucose are very common in insects. Thus its expected that scorpions and spiders which feed on insects present high activities of fucosidase. Our group is studying carbohydrases involved in digestion from digestive juice and hepatopancreas from the spider Nephliengys cruentata. Alpha-fucosidase activity was identified and characterized. Arthropoda alpha-fucosidase has been, till this moment, only characterized in Nephilengys cruentata and in the Crustacea Penaeus monodon and Chamagnatus granulata. This project aims to isolate and characterize the digestive alpha-fucosidases from the spider Nephilengys cruentata and from the scorpion Tityus serrulatus. Besides that carbohydrases involved in digestion from Tityus serrulatus will also be characterized using natural and synthetic substrates on homogenate samples and chromatographic fractions. | |