Multivalent γ-PGA-Exendin-4 Conjugates to Target Pancreatic β-Cells.

Targeting of glucagon-like peptide 1 receptor (GLP-1R), expressed on the surface of pancreatic β-cells, is of great interest for the development of advanced therapies for diabetes and diagnostics for insulinoma. We report the conjugation of exendin-4 (Ex-4), an approved drug to treat type 2 diabetes, to poly-γ-glutamic acid (γ-PGA) to obtain more stable and effective GLP-1R ligands. Exendin-4 modified at Lysine-27 with PEG4-maleimide was conjugated to γ-PGA functionalized with furan, in different molar ratios, exploiting a chemoselective Diels-Alder cycloaddition.

Biopolymer based nanosystem for doxorubicin targeted delivery.

This study describes formation of an actively and passively targeted, water-soluble drug delivery system (DDS) which contains doxorubicin (DOX). The system comprises two biocompatible and biodegradable polymers: poly-γ-glutamic acid (PGA) and chitosan (CH). Self-assembly of these biopolymers in aqueous medium results stable nanoparticles (NPs) with a hydrodynamic size of 80-150 nm and slightly negative surface charge.

α-Amylase Modulation: Discovery of Inhibitors Using a Multi-Pharmacophore Approach for Virtual Screening.

Better control of postprandial hyperglycemia can be achieved by delaying the absorption of glucose resulting from carbohydrate digestion. Because α-amylase initiates the hydrolysis of polysaccharides, the design of α-amylase inhibitors can lead to the development of new treatments for metabolic disorders such as type II diabetes and obesity. In this study, a rational computer-aided approach was developed to identify novel α-amylase inhibitors.

Anthocyanin composition, antioxidant efficiency, and α-amylase inhibitor activity of different Hungarian sour cherry varieties (Prunus cerasus L.).

Five Hungarian sour cherry cultivars were studied to determine their anthocyanin contents and their possible inhibitory properties. The water and methanol soluble antioxidant capacities were separately assessed by photoluminescence showing values ranged from 3.4μgmg(-1) to 15.

From carbohydrates to drug-like fragments: Rational development of novel α-amylase inhibitors.

Starch catabolism leading to high glucose level in blood is highly problematic in chronic metabolic diseases, such as type II diabetes and obesity. α-Amylase catalyzes the hydrolysis of starch, increasing blood sugar concentration. Its inhibition represents a promising therapeutic approach to control hyperglycaemia.

Optimization of triacetylfusarinine C and ferricrocin productions in Aspergillus fumigatus.

Iron is an essential element for all microorganisms. Bacteria and fungi produce versatile siderophores for binding and storing this essential transition metal when its availability is limited in the environment. The aim of the study was to optimize the fermentation medium of Aspergillus fumigatus for siderophore production.

Unexpected mode of action of sweet potato β-amylase on maltooligomer substrates.

β-Amylase (EC 3.2.1.

Model for β-1,6-N-acetylglucosamine oligomer hydrolysis catalysed by DispersinB, a biofilm degrading enzyme.

DispersinB (DspB), a member of β-1,6-N-acetylglucosaminidase group of GH 20 glycoside hydrolases, catalyses the biofilm degradation of several human pathogenic microorganisms. DspB is a (β/α)(8) barrel protein, showing retaining cleavage mechanism towards oligomer and polymer substrates. A chromophore containing oligomer substrate series was used to study the DspB's mode of action.

Synthesis of β-(1→6)-linked N-acetyl-D-glucosamine oligosaccharide substrates and their hydrolysis by Dispersin B.

Dispersin B (DspB) from Aggregatibacter actinomycetemcomitans is a β-hexosaminidase exhibiting biofilm detachment activity. A series of β-(1→6)-linked N-acetyl-D-glucosamine thiophenyl glycosides with degree of polymerisation (DP) of 2, 3, 4 and 5 were synthesized, and substrate specificity of DspB was studied on the obtained oligosaccharides. For oligomer synthesis a 1+2, 2+2, 1+4 coupling strategy was applied, using bromo-sugars as glycosyl donors.