Crystallization and preliminary crystallographic analysis of Abp, a GH27 β-L-arabinopyranosidase from Geobacillus stearothermophilus.

Geobacillus stearothermophilus T-6 is a thermophilic soil bacterium that possesses an extensive system for the utilization of hemicellulose. The bacterium produces a small number of endo-acting extracellular enzymes that cleave high-molecular-weight hemicellulolytic polymers into short decorated oligosaccharides, which are further hydrolysed into the respective sugar monomers by a battery of intracellular glycoside hydrolases. One of these intracellular processing enzymes is β-L-arabinopyranosidase (Abp), which is capable of removing β-L-arabinopyranose residues from naturally occurring arabino-polysaccharides.

Crystallization and preliminary crystallographic analysis of Axe2, an acetylxylan esterase from Geobacillus stearothermophilus.

Acetylxylan esterases are part of the hemi-cellulolytic system of many microorganisms which utilize plant biomass for growth. Xylans, which are polymeric sugars that constitute a significant part of the plant biomass, are usually substituted with acetyl side groups attached at position 2 or 3 of the xylose backbone units. Acetylxylan esterases hydrolyse the ester linkages of the xylan acetyl groups and thus improve the ability of main-chain hydrolysing enzymes to break down the sugar backbone units.

Regulation of protein catabolism by muscle-specific and cytokine-inducible ubiquitin ligase E3alpha-II during cancer cachexia.

The progressive depletion of skeletal muscle is a hallmark of many types of advanced cancer and frequently is associated with debility, morbidity, and mortality. Muscle wasting is primarily mediated by the activation of the ubiquitin-proteasome system, which is responsible for degrading the bulk of intracellular proteins. E3 ubiquitin ligases control polyubiquitination, a rate-limiting step in the ubiquitin-proteasome system, but their direct involvement in muscle protein catabolism in cancer remains obscure.

Mapping glycoside hydrolase substrate subsites by isothermal titration calorimetry.

Relating thermodynamic parameters to structural and biochemical data allows a better understanding of substrate binding and its contribution to catalysis. The analysis of the binding of carbohydrates to proteins or enzymes is a special challenge because of the multiple interactions and forces involved. Isothermal titration calorimetry (ITC) provides a direct measure of binding enthalpy (DeltaHa) and allows the determination of the binding constant (free energy), entropy, and stoichiometry.

Influence of insulin therapy on burn wound healing in rats.

Background: Insulin is proposed as a therapy for suppressing muscle wasting after burn trauma although the long-term effects of this therapy on wound healing are not yet known. The present study was designed to investigate the effect of systemically administered insulin therapy on burn wound healing.

Materials And Methods: Young rats weighing 80-150 g were subjected to 15-20% total body surface area burn injury on their shaved dorsum.

Antiproteolytic action of insulin in burn-injured rats.

Background: Negative nitrogen balance is a typical metabolic response to burn injury resulting in decreased muscle mass and activity. Since insulin is an anabolic hormone, using insulin as a prophylactic agent in burned patients has received some attention. The present study was carried out to investigate the systemic effect of insulin on burn injury-induced muscle wasting.