Strategies for improving expression of recombinant human chorionic gonadotropin in Chinese Hamster Ovary (CHO) cells.

Optimizations of the gene expression cassette combined with the selection of an appropriate signal peptide are important factors that must be considered to enhance heterologous protein expression in Chinese Hamster Ovary (CHO) cells. In this study, we investigated the effectiveness of different signal peptides on the production of recombinant human chorionic gonadotropin (r-hCG) in CHO-K1 cells. Four optimized expression constructs containing four promising signal peptides were stably transfected into CHO-K1 cells.

Effect of lignin content on a GH11 endoxylanase acting on glucuronoarabinoxylan-lignin nanocomposites.

The effects of lignin content on the activity and action pattern of GH11 endoxylanase from Thermobacillus xylanilyticus were investigated using in vitro reconstituted non-covalent glucuronoarabinoxylan-model lignin (GAX-DHP) nanocomposites. Four types of nanocomposites were prepared, each displaying different lignin contents. Variations in the DHP (model lignin) polymerization process were induced by increasing the coniferyl alcohol concentration.

Caldimonas hydrothermale sp. nov., a novel thermophilic bacterium isolated from Roman hot bath in south Tunisia.

A polyphasic approach was used to characterize a bacterium, HAN-85(T), isolated from thermal water in natural thermal spring at Tozeur, an oasis in southwest Tunisia. The novel isolate was thermophilic, strictly aerobic and amylolytic bacterium, which stained Gram negative. Cells were short rods motile by means of a single polar flagellum.

In vitro model assemblies to study the impact of lignin-carbohydrate interactions on the enzymatic conversion of xylan.

Endo-beta-1,4-xylanases (EC 3.2.1.

New insights into the role of the thumb-like loop in GH-11 xylanases.

GH-11 xylanases are highly specific and possess a thumb-shaped loop, a unique structure among enzymes with a jelly-roll scaffold. To investigate this structure, in vitro mutagenesis was performed on a GH-11 xylanase (Tx-Xyl) from Thermobacillus xylanilyticus. Targets were the conserved amino acids Pro(114)-Ser(115)-Ile(116) that are located at the thumb's tip and Thr(121) and Tyr(111), linker residues that connect the thumb to the main enzyme scaffold.