16 WINTER 1999 YMMETRY IS A FAMILIAR CONCEPT in art and design. In daily conversation, it usually refers to transformations in space, such as rotations of an object about an axis. In science, the word has a more general meaning and a profound significance, because its role in understanding the laws of Nature has been one of the dominant themes in physics. It figured heavily, for example, in muc...

Clostridium difficile, a leading cause of hospital-acquired infection, possesses a dense surface layer (S-layer) that mediates host-pathogen interactions. The key structural components of the S-layer result from proteolytic cleavage of a precursor protein, SlpA, into high- and low-molecular-weight components. Here we report the discovery and optimization of the first inhibitors of this process ...

S-layer protein isolated from Bacillus coagulans E38-66 could be recrystallized into large-scale coherent monolayers at an air/water interface and on phospholipid films spread on a Langmuir-Blodgett trough. Because of the asymmetry in the physiochemical surface properties of the S-layer protein, the subunits were associated with their more hydrophobic outer face with the air/water interface and...

Lysinibacillus sphaericus strains belonging the antigenic group H5a5b produce spores with larvicidal activity against larvae of Culex mosquitoes. C7, a new isolated strain, which presents similar biochemical characteristics and Bin toxins in their spores as the reference strain 2362, was, however, more active against larvae of Culex mosquitoes. The contribution of the surface layer protein (S-l...

The structure of a passivating sulfide layer on Ge(001) was studied using X-ray standing waves and X-ray fluorescence. The sulfide layer was formed by reacting clean Ge substrates in 42 solutions of various concentrations at 80°C. For each treatment, a sulfide layer containing approximately two to three monolayers (ML) of S was formed on the surface, and an ordered structure was found at the in...