The importance of the non-active site and non-periodical structure located histidine residue respect to the structure and function of exo-inulinase.

Here, we have studied the role of a histidine residue with the lowest solvent accessibility among other histidine residues at the end of a short connecting structure (AELH) of the catalytic domain of the exo-inulinase through creation of H192A mutant. Site-directed mutagenesis method was applied to create the mutant enzyme. Molecular dynamics (MD) simulations, spectroscopic, calorimetric and kinetics analysis were used to study the structural and functional consequences of His192 substitution.

Deletion of loop fragment adjacent to active site diminishes the stability and activity of exo-inulinase.

Inulinases are classified as hydrolases and widely used in the food and medical industries. Here, we report the deletion of a six-membered adjacent active site loop fragment (YGSDVT sequence) from third Ω-loop of the exo-inulinase containing aspartate residue from Aspergillus niger to study its structural and functional importance. Site-directed mutagenesis was used to create the mutant of the exo-inulinase (Δ6SL).

An Alternative Bacterial Expression System Using SG2 Chitinase Promoter.

Background: Chitin is an abundant natural polysaccharide found in fungi, algae, and exoskeleton of insects. Several bacterial species are capable of utilizing chitin as their carbon source. These bacteria produce chitinases for degradation of chitin into -acetyl-D-glucosamine.

Optimization of extracellular truncated staphylococcal protein A expression in Escherichia coli BL21 (DE3).

Staphylococcal protein A (SpA) plays an important role in Staphylococcus aureus pathogenesis. The recombinant SpA is also widely used in biotechnology to purify polyclonal and monoclonal immunoglobulin G antibodies. In this study, expression and secretion of a truncated form of SpA containing five immunoglobulin-binding domains using its own native signal sequence were optimized in Escherichia coli.

Regulation of GSK-3beta and beta-Catenin by Galphaq in HEK293T cells.

Recent studies have shown that heterotrimeric G proteins are involved in the regulation of the canonical Wnt/beta-Catenin pathway. However, the mechanism(s) behind this involvement is (are) poorly understood. Our previous results have shown that activation of Galphaq in Xenopus oocytes leads to inhibition of GSK-3beta and stabilization of the beta-Catenin protein, suggesting that Galphaq might stabilize beta-Catenin via inhibition of GSK-3beta.