Family Firms and Firm Performance: Evidence from Japan

Corrigendum: Nature Structural and Molecular Biology 16 (12), 1331 (2009) doi:10.1038/nsmb1209-1331bInternational audienceThioredoxins (Trxs) are oxidoreductase enzymes, present in all organisms, that catalyze the reduction of disulfide bonds in proteins. By applying a calibrated force to a substrate disulfide, the chemical mechanisms of Trx catalysis can be examined in detail at the single-molecule level. Here we use single-molecule force-clamp spectroscopy to explore the chemical evolution of Trx catalysis by probing the chemistry of eight different Trx enzymes. All Trxs show a characteristic Michaelis-Menten mechanism that is detected when the disulfide bond is stretched at low forces, but at high forces, two different chemical behaviors distinguish bacterial-origin from eukaryotic-origin Trxs. Eukaryotic-origin Trxs reduce disulfide bonds through a single-electron transfer reaction (SET), whereas bacterial-origin Trxs show both nucleophilic substitution (SN2) and SET reactions. A computational analysis of Trx structures identifies the evolution of the binding groove as an important factor controlling the chemistry of Trx catalysis

Profile of ustekinumab and its potential in patients with moderate-to-severe Crohn's disease

Anne Tuskey, Brian W Behm Division of Gastroenterology and Hepatology, University of Virginia School of Medicine, Charlottesville, VA, USA Abstract: The advent of anti-tumor necrosis factor (TNF)-α therapy has been a major advance in the medical management of Crohn's disease (CD). However, a significant proportion of patients with CD do not respond adequately to treatment with these agents. Primary and secondary nonresponse to anti-TNFα therapy represents a common clinical challenge, and highlights the need for the development of additional medication options for CD. The proinflammatory cytokines interleukin (IL)-12 and IL-23 are thought to play a key role in the pathogenesis of CD, and serve as a potential target for additional biologic therapies. Monoclonal antibodies targeting IL-12/23 have shown efficacy in animal models of colitis, and are currently being studied in Phase III clinical trials of CD. This review focuses on ustekinumab, a fully human immunoglobulin G1 monoclonal antibody, which blocks activity of IL-12 and IL-23 through binding the p40 subunit, and describes the current efficacy and safety data for ustekinumab in patients with CD. Keywords: Crohn's disease, ustekinumab, clinical trials, inflammatory bowel diseas