Regulatory properties of vitronectin and its glycosylation in collagen fibril formation and collagen-degrading enzyme cathepsin K activity.

Vitronectin (VN) is a glycoprotein found in extracellular matrix and blood. Collagen, a major extracellular matrix component in mammals, is degraded by cathepsin K (CatK), which is essential for bone resorption under acidic conditions. The relationship between VN and cathepsins has been unclear.

α-Amylase expressed in human small intestinal epithelial cells is essential for cell proliferation and differentiation.

α-Amylase, which plays an essential role in starch degradation, is expressed mainly in the pancreas and salivary glands. Human α-amylase is also detected in other tissues, but it is unclear whether the α-amylase is endogenously expressed in each tissue or mixed exogenously with one expressed by the pancreas or salivary glands. Furthermore, the biological significance of these α-amylases detected in tissues other than the pancreas and salivary glands has not been elucidated.

Preparation and Purification of Active Recombinant Human Pancreatic Lipase in .

Human pancreatic lipase (HPL) is the main lipolytic enzyme involved in the digestion of dietary fat. An active recombinant human pancreatic lipase (recHPL) was successfully prepared for the first time in an ) expression system using a short Strep-tag II (ST II). The recHPL-ST II was solubilized with 8 M urea from the lysate and purified on a Strep-Tactin-Sepharose column.

Vitronectins produced by human cirrhotic liver and CCl-treated rats differ in their glycosylation pattern and tissue remodeling activity.

Liver cirrhosis (LC) is a disease characterized by pathological accumulation and alteration of extracellular matrix (ECM) proteins; the interaction between two such proteins, collagen and vitronectin (VN), is considered to be the key to controlling ECM remodeling in liver cirrhosis. If it is possible to control the modification of oligosaccharides on VN, it may be possible to retard progression of liver cirrhosis. In this study, we examined the relationship between changes in VN glycosylation and activity related to the remodeling of hepatic tissue in human LC and a rat model of LC generated using carbon tetrachloride (CCl).

A novel protocol for the preparation of active recombinant human pancreatic lipase from Escherichia coli.

An active recombinant human pancreatic lipase (recHPL) was successfully prepared for the first time from the Escherichia coli expression system using short Strep-tag II (ST II). The recHPL-ST II was solubilized using 8 M urea from E.coli lysate and purified on a Strep-Tactin-Sepharose column.

The serum protein renalase reduces injury in experimental pancreatitis.

Acute pancreatitis is a disease associated with inflammation and tissue damage. One protein that protects against acute injury, including ischemic injury to both the kidney and heart, is renalase, which is secreted into the blood by the kidney and other tissues. However, whether renalase reduces acute injury associated with pancreatitis is unknown.

Sialylation of vitronectin regulates stress fiber formation and cell spreading of dermal fibroblasts via a heparin-binding site.

Vitronectin (VN) plays an important role in tissue regeneration. We previously reported that VN from partial hepatectomized (PH) rats results in a decrease of sialylation of VN and de-sialylation of VN decreases the cell spreading of hepatic stellate cells. In this study, we analyzed the mechanism how sialylation of VN regulates the properties of mouse primary cultured dermal fibroblasts (MDF) and a dermal fibroblast cell line, Swiss 3T3 cells.

Carbohydrate-binding activities of coagulation factors fibrinogen and fibrin.

The coagulation factors fibrinogen and fibrin play important roles in the final stage of the blood coagulation cascade. It has not been revealed whether fibrinogen has lectin activity or not. Here we demonstrate that fibrinogen and fibrin have carbohydrate-specific binding activities that inhibit fibrin clot formation.

Pancreatic α-Amylase Controls Glucose Assimilation by Duodenal Retrieval through N-Glycan-specific Binding, Endocytosis, and Degradation.

α-Amylase, a major pancreatic protein and starch hydrolase, is essential for energy acquisition. Mammalian pancreatic α-amylase binds specifically to glycoprotein N-glycans in the brush-border membrane to activate starch digestion, whereas it significantly inhibits glucose uptake by Na(+)/glucose cotransporter 1 (SGLT1) at high concentrations (Asanuma-Date, K., Hirano, Y.

Autoactivation of pancreatic trypsinogen is controlled by carbohydrate-specific interaction.

Activation of bovine pancreatic trypsinogen (BPTG) by trypsin (BPT) was found to be inhibited by d GalN/GalNAc at pH 5.5, the pH of secretory granules in the pancreas. Binding studies with biotinylated sugar-polymers indicated that BPTG and BPT bind to α-GalNAc, α-Man, and α-Gal better at pH 5.

Preparation of affinity adsorbents and purification of lectins from natural sources.

Lectins are purified by affinity chromatography to take advantage of their carbohydrate-specific interactions. Highly efficient affinity adsorbents are powerful tools to obtain homogeneous lectins with distinct specificities. Here, we describe three methods to prepare affinity adsorbents by immobilizing carbohydrates or glycoconjugates on agarose gel beads.

The "white kidney bean incident" in Japan.

Lectin poisoning occurred in Japan in 2006 after a TV broadcast that introduced a new diet of eating staple foods with powdered toasted white kidney beans, seeds of Phaseolus vulgaris. Although the method is based on the action of a heat-stable α-amylase inhibitor in the beans, phaseolamin, more than 1,000 viewers who tried the method suffered from acute intestinal symptoms and 100 people were hospitalized. Lectins in the white kidney beans were suspected to be the cause of the trouble.

Survival signals of hepatic stellate cells in liver regeneration are regulated by glycosylation changes in rat vitronectin, especially decreased sialylation.

The extracellular matrix (ECM) molecules play important roles in many biological and pathological processes. During tissue remodeling, the ECM molecules that are glycosylated are different from those of normal tissue owing to changes in the expression of many proteins that are responsible for glycan synthesis. Vitronectin (VN) is a major ECM molecule that recognizes integrin on hepatic stellate cells (HSCs).