An aspartic proteinase was isolated from American lobster gastric fluid. The purified cathepsin D runs as a single band on native-PAGE displaying proteolytic activity on a zymogram at pH 3.0, with an isoelectric point of 4.7. Appearance of the protein in SDS-PAGE, depended on the conditions of the gel electrophoresis. SDS treatment by itself was not able to fully unfold the protein. Thus, in SD...

Digestive juice from the herbivorous gecarcinid land crabs Gecarcoidea natalis and Discoplax hirtipes exhibited total cellulase activity and activities of two cellulase enzymes; endo-beta-1,4-glucanase and beta-1,4-glucosidase. These enzymes hydrolysed native cellulose to glucose. The digestive juice of both species also contained laminarinase, licheninase and xylanase, which hydrolysed laminar...

BACKGROUND Due to the high proline content of gluten molecules, gastrointestinal proteases are unable to fully degrade them leaving large proline-rich gluten fragments intact, including an immunogenic 33-mer from α-gliadin and a 26-mer from γ-gliadin. These latter peptides can trigger pro-inflammatory T cell responses resulting in tissue remodeling, malnutrition and a variety of other complicat...

Digestive proteinase activities of Artemesia longinaris were assayed at different stages of the molting cycle. Total proteolytic activity in the hepatopancreas was highest during postmolt. Trypsin and chymotrypsin activities were highest during intermolt. Specific inhibitors and zymograms of A. longinaris hepatopancreas extracts showed four trypsins (14.79, 15.49, 16.60, 17.38 kDa, respectively...

PURPOSE OF REVIEW Genetic risk in chronic pancreatitis is partly due to mutations that cause misfolding of digestive enzymes and elicit endoplasmic reticulum stress. This review examines recent developments in this concept. RECENT FINDINGS The best characterized misfolding variants in the highly expressed digestive proteases cationic trypsinogen (PRSS1) and carboxypeptidase A1 (CPA1) are stro...

The digestive system of any animal is important in converting the food the animal eats into the nutrients its body needs for growth, maintenance, and production (such as egg production). An animal's body breaks down food through both mechanical and chemical means. In many animals, mechanical action involves chewing; however, because birds do not have teeth, their bodies use other mechanical act...

Background Wood-feeding termite, Coptotermes formosanus Shiraki, represents a highly efficient system for biomass deconstruction and utilization. However, the detailed mechanisms of lignin modification and carbohydrate degradation in this system are still largely elusive. Results In order to reveal the inherent mechanisms for efficient biomass degradation, four different organs (salivary glan...

Until recently, it was considered impossible to feed newly hatched marine fish species with a compound diet. Substituting a compound diet for live prey was performed several weeks after hatching, depending on the species. Compound diets were well ingested at the early stage but larvae died with a gut full of food, suggesting that larvae were unable to digest the compound diet. The hypothesis wa...

The intracellular distribution and level of acid hydrolases in Ochromonas malhamensis were studied in cells grown osmotrophically in a defined medium, in a carbon-free starvation medium, and during phagotrophy in each of these media. By cytochemical techniques, little enzymic reaction product was observed in the vacuoles of osmotrophic cells grown in the defined medium. Starved cells, however, ...