The effects of glucosamine sulfate on intervertebral disc annulus fibrosus cells in vitro.

Background Context: Glucosamine has gained widespread use among patients, despite inconclusive efficacy data. Inconsistency in the clinical literature may be related to lack of understanding of the effects of glucosamine on the intervertebral disc, and therefore, improper patient selection.

Purpose: The goal of our study was to investigate the effects of glucosamine on intervertebral disc cells in vitro under the physiological conditions of inflammation and mechanical loading.

In vitro and in vivo analyses of the Bacillus anthracis spore cortex lytic protein SleL.

The bacterial endospore is the most resilient biological structure known. Multiple protective integument layers shield the spore core and promote spore dehydration and dormancy. Dormancy is broken when a spore germinates and becomes a metabolically active vegetative cell.

In vitro studies of peptidoglycan binding and hydrolysis by the Bacillus anthracis germination-specific lytic enzyme SleB.

The Bacillus anthracis endospore loses resistance properties during germination when its cortex peptidoglycan is degraded by germination-specific lytic enzymes (GSLEs). Although this event normally employs several GSLEs for complete cortex removal, the SleB protein alone can facilitate enough cortex hydrolysis to produce vulnerable spores. As a means to better understand its enzymatic function, SleB was overexpressed, purified, and tested in vitro for depolymerization of cortex by measurement of optical density loss and the solubilization of substrate.

Contributions of four cortex lytic enzymes to germination of Bacillus anthracis spores.

Bacterial spores remain dormant and highly resistant to environmental stress until they germinate. Completion of germination requires the degradation of spore cortex peptidoglycan by germination-specific lytic enzymes (GSLEs). Bacillus anthracis has four GSLEs: CwlJ1, CwlJ2, SleB, and SleL.