Correction: Comparison of the molecular properties of retinitis pigmentosa P23H and N15S amino acid replacements in rhodopsin.

[This corrects the article DOI: 10.1371/journal.pone.

Comparison of the molecular properties of retinitis pigmentosa P23H and N15S amino acid replacements in rhodopsin.

Mutations in the RHO gene encoding for the visual pigment protein, rhodopsin, are among the most common cause of autosomal dominant retinitis pigmentosa (ADRP). Previous studies of ADRP mutations in different domains of rhodopsin have indicated that changes that lead to more instability in rhodopsin structure are responsible for more severe disease in patients. Here, we further test this hypothesis by comparing side-by-side and therefore quantitatively two RHO mutations, N15S and P23H, both located in the N-terminal intradiscal domain.

Amyloid-β-Secondary Structure Distribution in Cerebrospinal Fluid and Blood Measured by an Immuno-Infrared-Sensor: A Biomarker Candidate for Alzheimer's Disease.

The misfolding of the Amyloid-beta (Aβ) peptide into β-sheet enriched conformations was proposed as an early event in Alzheimer's Disease (AD). Here, the Aβ peptide secondary structure distribution in cerebrospinal fluid (CSF) and blood plasma of 141 patients was measured with an immuno-infrared-sensor. The sensor detected the amide I band, which reflects the overall secondary structure distribution of all Aβ peptides extracted from the body fluid.

An infrared sensor analysing label-free the secondary structure of the Abeta peptide in presence of complex fluids.

The secondary structure change of the Abeta peptide to beta-sheet was proposed as an early event in Alzheimer's disease. The transition may be used for diagnostics of this disease in an early state. We present an Attenuated Total Reflection (ATR) sensor modified with a specific antibody to extract minute amounts of Abeta peptide out of a complex fluid.

Mechanism of scrapie prion precipitation with phosphotungstate anions.

The phosphotungstate anion (PTA) is widely used to facilitate the precipitation of disease-causing prion protein (PrP(Sc)) from infected tissue for applications in structural studies and diagnostic approaches. However, the mechanism of this precipitation is not understood. In order to elucidate the nature of the PTA interaction with PrP(Sc) under physiological conditions, solutions of PTA were characterized by NMR spectroscopy at varying pH.

It's in your blood: spectral biomarker candidates for urinary bladder cancer from automated FTIR spectroscopy.

Blood samples of urinary bladder cancer (UBC) patients and patients with urinary tract infection were analysed with advanced automated high throughput Fourier transform infrared (HT-FTIR)-spectroscopy. Thin dried film samples were robotically prepared on multi-well titer plates (MTP) for absorbance measurements in transmission mode. Within the absorbance, 1st and 2nd derivative spectra of serum and two plasma preparations, discriminative patterns were identified and validated using bioinformatic tools.

FTIR spectroscopy of biofluids revisited: an automated approach to spectral biomarker identification.

The extraction of disease specific information from Fourier transform infrared (FTIR) spectra of human body fluids demands the highest standards of accuracy and reproducibility of measurements because the expected spectral differences between healthy and diseased subjects are very small in relation to a large background absorbance of the whole sample. Here, we demonstrate that with the increased sensitivity of modern FTIR spectrometers, automatisation of sample preparation and modern bioinformatics, it is possible to identify and validate spectral biomarker candidates for distinguishing between urinary bladder cancer (UBC) and inflammation in suspected bladder cancer patients. The current dataset contains spectra of blood serum and plasma samples of 135 patients.

Natural and synthetic prion structure from X-ray fiber diffraction.

A conformational isoform of the mammalian prion protein (PrP(Sc)) is the sole component of the infectious pathogen that causes the prion diseases. We have obtained X-ray fiber diffraction patterns from infectious prions that show cross-beta diffraction: meridional intensity at 4.8 A resolution, indicating the presence of beta strands running approximately at right angles to the filament axis and characteristic of amyloid structure.

Surface charge of polyoxometalates modulates polymerization of the scrapie prion protein.

Prions are composed solely of an alternatively folded isoform of the prion protein (PrP), designated PrP(Sc). N-terminally truncated PrP(Sc), denoted PrP 27-30, retains infectivity and polymerizes into rods with the ultrastructural and tinctorial properties of amyloid. We report here that some polyoxometalates (POMs) favor polymerization of PrP 27-30 into prion rods, whereas other POMs promote assembly of the protein into 2D crystals.

Conformational diversity of wild-type Tau fibrils specified by templated conformation change.

Tauopathies are sporadic and genetic neurodegenerative diseases characterized by aggregation of the microtubule-associated protein Tau. Tau pathology occurs in over 20 phenotypically distinct neurodegenerative diseases, including Alzheimer disease and frontotemporal dementia. The molecular basis of this diversity among sporadic tauopathies is unknown, but distinct fibrillar wild-type (WT) Tau conformations could play a role.

Structural changes of membrane-anchored native PrP(C).

Misfolding and subsequent aggregation of endogenous proteins constitute essential steps in many human disorders, including Alzheimer and prion diseases. In most prion protein-folding studies, the posttranslational modifications, the lipid anchor in particular, were lacking. Here, we studied a fully posttranslationally modified cellular prion protein, carrying two N-glycosylations and the natural GPI anchor.

Prion protein alpha-to-beta transition monitored by time-resolved Fourier transform infrared spectroscopy.

The conformational change of the recombinant, murine prion protein (PrP) from an alpha-helical to a beta-sheet enriched state was monitored by time-resolved Fourier transform infrared (FT-IR) spectroscopy. The alpha-to-beta transition is induced by reduction of the single disulfide bond in PrP. This transition is believed to generate the scrapie form PrP(Sc), the supposed infectious agent of transmissible spongiform encephalopathies.

A unique sequence motif in the 54-kDa subunit of the chloroplast signal recognition particle mediates binding to the 43-kDa subunit.

Chloroplasts contain a novel type of signal recognition particle (cpSRP) that consists of two proteins, cpSRP54 and cpSRP43. cpSRP is involved in the post-translational targeting of the nuclear encoded light-harvesting chlorophyll-binding proteins (LHCPs) to the thylakoid membrane by forming a soluble cpSRP.LHCP transit complex in the stroma.

De novo design of conformationally flexible transmembrane peptides driving membrane fusion.

Fusion of biological membranes is mediated by distinct integral membrane proteins, e.g., soluble N-ethylmaleimide-sensitive factor attachment protein receptors and viral fusion proteins.