The serine proteases sequentially activated to form a fibrin clot are inhibited primarily by members of the serpin family, which use a unique beta-sheet expansion mechanism to trap and destroy their targets. Since the discovery that serpins were a family of serine protease inhibitors there has been controversy as to the role of conformational change in their mechanism. It now is clear that prot...

An approach involving the systematic computational conformational analysis of all overlapping hexapeptide segments in the protein sequence has found fragments with the higher than average propensity to adopt the native-like three-dimensional structure and other regular nonrandom structures in the unfolded states of four beta-sheet proteins, namely IFABP (intestinal fatty acid-binding protein), ...

The physical properties of cuticle are determined by the structure of its two major components, cuticular proteins (CPs) and chitin, and, also, by their interactions. A common consensus region (extended R&R Consensus) found in the majority of cuticular proteins, the CPRs, binds to chitin. Previous work established that beta-pleated sheet predominates in the Consensus region and we proposed that...

To study the secondary structure of the enzyme NADPH: protochlorophyllide oxidoreductase (PCOR), a novel method of enzyme isolation was developed. The detergent isotridecyl poly-(ethylene glycol) ether (Genapol X-080) selectively solubilizes the enzyme from a prolamellar-body fraction isolated from wheat (Triticum aestivum L.). The solubilized fraction was further purified by ion-exchange chrom...

Native platelet factor 4 (PF4) (70 residues) has a hydrophobic three-stranded anti-parallel beta-sheet domain on to which is folded an amphipathic C-terminal alpha-helix and an aperiodic N-terminal domain. The 33-amino acid beta-sheet domain from PF4 (residues 23-55) has been synthesized and studied by c.d. and n.m.r. At 10 degrees C and low concentration, peptide 23-55 appears to exist in aque...

An active fragment was identified from tenecin 1, an antibacterial protein belonging to the insect defensin family, by synthesizing the peptides corresponding to the three regions of tenecin 1. Only the fragment corresponding to the C-terminal beta-sheet domain showed activity against fungi as well as Gram-positive and Gram-negative bacteria, whereas tenecin 1, the native protein, showed activi...

The Escherichia coli RecA protein triggers both DNA repair and mutagenesis in a process known as the SOS response. The 81-residue E. coli protein DinI inhibits activity of RecA in vivo. The solution structure of DinI has been determined by multidimensional triple resonance NMR spectroscopy, using restraints derived from two sets of residual dipolar couplings, obtained in bicelle and phage media...

Longicin, a defensin-like peptide, was recently identified in the hard tick Haemaphysalis longicornis. Longicin and one of its synthetic partial analogs (P4) displayed antimicrobial/fungicidal/parasiticidal activity. In the present study, we compared longicin-derived synthetic analogs in order to characterize the antimicrobial motif (P4) by analyzing some structural features using various bioin...

Tachylectin-2, isolated from large granules of the hemocytes of the Japanese horseshoe crab (Tachypleus tridentatus), is a 236 amino acid protein belonging to the lectins. It binds specifically to N-acetylglucosamine and N-acetylgalactosamine and is a part of the innate immunity host defense system of the horseshoe crab. The X-ray structure of tachylectin-2 was solved at 2.0 A resolution by the...

Acidic fibroblast growth factor from newt (Notopthalmus viridescens) is a approximately 15-kDa, all beta-sheet protein devoid of disulfide bonds. In the present study, we investigate the effects of 2,2,2-trifluoroethanol (TFE) on the structure of newt acidic fibroblast growth factor (nFGF-1). The protein aggregates maximally in 10% (v/v) TFE. Congo red and thioflavin T binding experiments sugge...