This paper describes elucidation of the conformation of the human epidermal growth factor (hEGF) in an aqueous environment, using one- and two-dimensional proton nuclear magnetic resonance methods. The noted structural information obtained is that a rigid core structure is formed by the interplay of the three disulfide bridges and an antiparallel beta-sheet consisting of Val-19 to Glu-24 and As...

Amyloids are highly organized cross-beta-sheet-rich protein or peptide aggregates that are associated with pathological conditions including Alzheimer's disease and type II diabetes. However, amyloids may also have a normal biological function, as demonstrated by fungal prions, which are involved in prion replication, and the amyloid protein Pmel17, which is involved in mammalian skin pigmentat...

A novel ELISA has been developed which detects oligomerization of beta-amyloid (A beta). Oligomerization, fibrillization and neurotoxicity of native A beta associated with Alzheimer's disease (AD) type has been compared with E22Q A beta (amyloid beta-protein containing residues 1--40 with the native Glu at residue 22 changed to Gln) implicated in Dutch cerebral haemorrhage disease. Solutions of...

Protegrins are short, cationic peptides that display potent, broad-spectrum antimicrobial activity. PG-1, the first of the five natural analogues discovered, forms a rigid antiparallel two-stranded beta-sheet that is stabilized by two disulfide bonds. The two strands of the sheet are linked by a short two-residue loop segment. Removal of the disulfide bridges (e.g., in Cys --> Ala analogues) is...

The main hypothesis for prion diseases proposes that the cellular protein (PrP(C)) can be altered into a misfolded, beta-sheet-rich isoform (PrP(Sc)), which undergoes aggregation and triggers the onset of transmissible spongiform encephalopathies. Here, we compare the stability against pressure and the thermomechanical properties of the alpha-helical and beta-sheet conformations of recombinant ...

An amyloid(1-40) solution rich in coil, turn, and alpha-helix, but poor in beta-sheet, develops monolayers with a high beta-sheet content when spread at the air-water interface. These monolayers are resistant to repeated compression-dilatation cycles and interaction with trifluoroethanol. The secondary structure motifs were detected by circular dichroism (CD) in solution and with infrared refle...

The secondary structure and thermal stability of the extrinsic 23 kDa protein (OEC23) of spinach photosystem II have been characterized in solution between 25 and 75 degrees C using Fourier transform infrared spectroscopy. Quantitative analysis of the amide I band (1700-1600 cm(-1)) shows that OEC23 contains 5% alpha-helix, 37% beta-sheet, 24% turn, and 34% disorder structures at 25 degrees C. ...

beta-Sheet antimicrobial peptides and alpha-helical channel-forming colicins are bactericidal molecules that target the lipid membranes of sensitive cells. Understanding the mechanisms of action of these proteins requires knowledge of their three-dimensional structure in the lipid bilayer. Solid-state NMR has been used to determine the conformation, orientation, depth of insertion, oligomerizat...

RPB5 is an essential subunit of eukaryotic and archaeal RNA polymerases. It is a proposed target for transcription activator proteins in eukaryotes, but the mechanism of interaction is not known. We have determined the solution structure of the RPB5 subunit from the thermophilic archeon, Methanobacterium thermoautotrophicum. MtRBP5 contains a four-stranded beta-sheet platform supporting two alp...

Fundamental questions about the relative arrangement of the beta-sheet arrays within amyloid fibrils remain central to both its structure and the mechanism of self-assembly. Recent computational analyses suggested that sheet-to-sheet lamination was limited by the length of the strand. On the basis of this hypothesis, a short seven-residue segment of the Alzheimer's disease-related Abeta peptide...