Addition of sugars such as sucrose to aqueous protein solutions generally stabilizes proteins against thermal denaturation by preferential exclusion from (preferential hydration proteins). In this study, we investigated the effect sucralose, a chlorinated derivative, on stability and solvation. Circular dichroism small-angle X-ray scattering measurements showed that increased temperature myoglobin was preferentially excluded protein, whereas sucralose decreased adsorbed protein. No clear...

The vacuum ultraviolet circular dichroism (VUVCD) spectra of 15 globular proteins (myoglobin, hemoglobin, human serum albumin, cytochrome c, peroxidase, alpha-lactalbumin, lysozyme, ovalbumin, ribonuclease A, beta-lactoglobulin, pepsin, trypsinogen, alpha-chymotrypsinogen, soybean trypsin inhibitor, and concanavalin A) were measured in aqueous solutions at 25 degrees C the wavelength region from 260 to 160 nm under a high vacuum, using synchrotron-radiation VUVCD spectrophotometer. below 190...

α-Synuclein (αS) interacts with lipid membranes in neurons to form amyloid fibrils that contribute Parkinson’s disease, and its non-amyloid-β component domain is critical the fibrillation. In this study, salt (NaCl) effect on membrane interaction fibril formation of αS57–102 peptide (containing domain) was characterized at molecular level because exhibited structural polymorphism two morphologies (thin thick) presence NaCl but showed one morphology (thin) absence NaCl. The membrane-bound...

Journal Article Improved Estimation of the Secondary Structures Proteins by Vacuum-Ultraviolet Circular Dichroism Spectroscopy Get access Koichi Matsuo, Matsuo *To whom correspondence should be addressed. E-mail: gekko@sci.hiroshima-u.ac.jp Search for other works this author on: Oxford Academic PubMed Google Scholar Ryuta Yonehara, Yonehara Kunihiko Gekko The Biochemistry, Volume 138, Issue 1, Jul. 2005, Pages 79–88, https://doi.org/10.1093/jb/mvi101 Published: 01 July 2005 history Received:...

Clusters of GM1 gangliosides act as platforms for conformational transition monomeric, unstructured amyloid β (Aβ) to its toxic β-structured aggregates. We have previously shown that Aβ(1-40) accommodated on the hydrophobic/hydrophilic interface lyso-GM1 or micelles assumes α-helical structures under ganglioside-excess conditions. For better understanding mechanisms underlying α-to-β Aβ clusters, we performed spectroscopic characterization titrated with GM1. It was revealed thioflavin T-...

Abstract Paenibacillus sp. strain FPU-7 produces several different chitinases and effectively hydrolyzes robust chitin. Among the P. chitinases, ChiW, a novel monomeric chitinase with molecular mass of 150 kDa, is expressed as cell surface molecule. Here, we report that active ChiW lacking anchoring domains in N-terminus was successfully overproduced Escherichia coli purified to homogeneity. The two catalytic at C-terminal region were classified typical glycoside hydrolase family 18 whereas...

We report here results of the first direct measurement partial volume and compressibility changes a protein as it forms an amyloid protofibril. use high precision density meter ultrasonic velocity on solution intrinsically denatured, disulfide-deficient variant hen lysozyme, follow time-dependent in compressibility, spontaneously have found large increase specific with time from 0.684 to 0.724 mL·g-1 (Δν = 0.040 corresponding 570 mL·(mol monomer)-1) adiabatic coefficient −7.48 × 10-12 +1.35...

The structures of the tetracyclic fusicoccanes roussoellols A (1) and B (2) from Roussoella hysterioides KT1651 are described. NMR spectroscopic analyses involving NOESY experiments revealed that these molecules possessed unique bent were supported by chemical derivatizations as well shift comparisons with theoretical shifts based on density functional theory (DFT) at EDF2/6-31G* level. Absolute configurations established ECD couplet positive chirality in both 1 2 vacuum UV (VUV) region,...

Abstract With the aim of measuring circular dichroism (CD) spectra biomaterials in aqueous solutions vacuum ultraviolet region between 310 and 140 nm, an optical system withstanding high was incorporated into beam line 15 Hiroshima Synchrotron Radiation Center (HiSOR). The performance constructed confirmed to be satisfactory high-vacuum on-line experiments by monitoring CD ammonium d-camphor-10-sulfonate, d- l-alanines water.

The electronic circular dichoism (ECD) of l-alanine in the vacuum-ultraviolet region was calculated for various optimized structures using time-dependent density functional theory (TDDFT) to assign CD spectrum observed experimentally aqueous solution down 140 nm [Matsuo, et al. Chem. Lett. 2002, 826]. structure vacuo (DFT) at B3LYP/6-31G* level. Its hydrated with nine water molecules (six and three around carboxyl amino groups, respectively) DFT a continuum model (Onsager model). dihedral...

Abstract To elucidate the structural characteristics of alcohol‐denatured proteins, we measured vacuum‐ultraviolet circular dichroism (VUVCD) spectra six proteins—myoglobin, human serum albumin, α‐lactalbumin, thioredoxin, β‐lactoglobulin, and α‐chymotrypsinogen A—down to 170 nm in trifluoroethanol solutions (TFE: 0−50%) down 175 methanol (MeOH: 0−70%) at pH 2.0 25°C, using a synchrotron‐radiation VUVCD spectrophotometer. The contents α‐helices, β‐strands, turns, poly‐ L ‐proline type II...

Abstract A vacuum-ultraviolet (VUV) circular-dichroism (CD) spectrophotometer usable down to 140 nm was constructed using synchrotron radiation and applied the structural analyses of various saccharides, amino acids, proteins in aqueous solutions. Most monosaccharides disaccharides exhibited a positive CD peak around 170 nm, depending on anomeric axial/equatorial configurations hydroxy groups, trans–gauche hydroxymethyl type glycosidic linkage. The VUVCD spectra glycosaminoglycans...

Abstract Homochirality is a fundamental feature of all known forms life, maintaining biomolecules (amino-acids, proteins, sugars, nucleic acids) in one specific chiral form. While this condition central to biology, the mechanisms by which adverse accumulation non- l- α-amino-acids proteins lead pathophysiological consequences remain poorly understood. To address how heterochirality build-up impacts organism’s health, we use chiral-selective vivo assays detect protein-bound non -l -α-amino...

The hallmark of amyloidosis, such as Alzheimer's disease and Parkinson's disease, is the deposition amyloid fibrils in various internal organs. onset related to strength cytotoxicity caused by toxic species. Furthermore, show polymorphism, where some types are cytotoxic while others not. It thus essential understand molecular mechanism cytotoxicity, part which interaction between polymorphic cell membranes. Here, using polymorphs hen egg white lysozyme, associated with hereditary systemic...

The elucidation of protein-membrane interactions is pivotal for comprehending the mechanisms underlying diverse biological phenomena and membrane-related diseases. In this investigation, vacuum-ultraviolet circular dichroism (VUVCD) spectroscopy, utilizing synchrotron radiation (SR), was employed to dynamically observe membrane interaction processes involving water-soluble proteins at secondary-structure level. study utilized a time-resolved (TR) T-shaped microfluidic cell, facilitating...

This research identified a marine fungal isolate, Aspergillus sp. strain GAD7, which produces an acidic and sulfated extracellular polysaccharide (EPS) with notable anticoagulant antioxidant properties. Six strains from the Egyptian Mediterranean Sea were screened for EPS production, GAD7 (EPS-AG7) being most potent, yielding ~5.19 ± 0.017 g/L. EPS-AG7 was characterized using UV-Vis FTIR analyses, revealing high carbohydrate (87.5%) sulfate (24%) contents. HPLC GC-MS analyses determined that...