Designed peptides that fold autonomously to specific conformations in aqueous solution are useful for elucidating protein secondary structural preferences. For example, autonomously folding model systems have been essential for establishing the relationship between a-helix length and a-helix stability, which would be impossible to probe with a-helices embedded in folded proteins. Here, we use d...

Filaments of all actin-like proteins known to date are assembled from pairs of protofilaments that are arranged in a parallel fashion, generating polarity. In this study, we show that the prokaryotic actin homologue MreB forms pairs of protofilaments that adopt an antiparallel arrangement in vitro and in vivo. We provide an atomic view of antiparallel protofilaments of Caulobacter MreB as appar...

We analysed the length distributions of different types of beta-strand in a high resolution, non-homologous set of 500 protein structures, finding differences in their mean lengths. Antiparallel edge strands in strand-turn-strand motifs show a preference for an even number of residues. This propensity is enhanced if the length is corrected for beta-bulges, which insert an extra residue into the...

During cell division, microtubules are arranged in a large bipolar structure, the mitotic spindle, to segregate the duplicated chromosomes. Antiparallel microtubule overlaps in the spindle center are essential for establishing bipolarity and maintaining spindle stability throughout mitosis. In anaphase, this antiparallel microtubule array is tightly bundled forming the midzone, which serves as ...

Introduction: Nowadays, the main focus of dental studies is on adhesive dental materials; since clinical long-term success of bonded restorations depended more on marginal microleakage minimization. So, the aim of this study was Evaluation of Diode laser irradiation effect on microleakage in class V composite restoration before and after adhesive application. Materials and methods: In this in v...

Formation of microtubule architectures, required for cell shape maintenance in yeast, directional cell expansion in plants and cytokinesis in eukaryotes, depends on antiparallel microtubule crosslinking by the conserved MAP65 protein family. Here, we combine structural and single molecule fluorescence methods to examine how PRC1, the human MAP65, crosslinks antiparallel microtubules. We find th...

In this paper, a simple statistical mechanical model for the antiparallel -sheet/coil equilibrium is constructed. It is based on the transfer matrix method, which has been widely used in the helix/coil transition theory. However, to correctly represent the structure of antiparallel -sheet, we have to extend the former numerical matrix to an 11 11 operator one. All calculation rules of the opera...

objectives: fluoride therapy is important for control and prevention of dental caries. laser irradiation can increase fluoride uptake especially when combined with topical fluoride application. the objective of this study was to compare the effects of co 2 and diode lasers on enamel fluoride uptake in primary teeth. materials and methods: forty human primary molars were randomly assigned to fou...