temporary banners

 



 

Journal Issue - Volume 12 Issue 4 (April 2003)

Abstract The final, structure‐determining step in the folding of membrane proteins involves the coalescence of preformed transmembrane helices to form the native tertiary structure. Here, we review recent studies on small peptide and protein systems that are providing quantitative data on the interactions that drive this process. Gel electrophoresis, analytical ultracentrifugation, and fluorescence resonance energy transfer (FRET)...

Abstract There are many kinds of silks from silkworms and spiders with different structures and properties, and thus, silks are suitable to study the structure‐property relationship of fibrous proteins. Silk fibroin from a wild silkworm, Samia cynthia ricini, mainly consists of the repeated similar sequences by about 100 times where there are alternative appearances of the polyalanine (Ala)12–13 region and the Gly‐rich region. In this paper, a...

Abstract We measured the denaturation and reassembly of Escherichia coli chaperonin GroEL using small‐angle solution X‐ray scattering, which is a powerful technique for studying the overall structure and assembly of a protein in solution. The results of the urea‐induced unfolding transition show that GroEL partially dissociates in the presence of more than 2 M urea, cooperatively unfolds at around 3 M urea, and is in a monomeric random...

Abstract The aim of this study was to develop new surfactants for membrane protein solubilization, from a natural, biodegradable polymer: the polysaccharide pullulan. A set of amphiphilic pullulans (HMCMPs), differing in hydrophobic modification ratio, charge ratio, and the nature of the hydrophobic chains introduced, were synthesized and tested in solubilization experiments with outer membranes of Pseudomonas fluorescens. The...

Abstract We have engineered a recombinant hemoglobin (rHb βG83C) based on the variant Hb Ta‐Li, which oligomerizes through intertetramer disulfide bonds. Size exclusion chromatography and electrospray ionization mass spectrometry show that the rHb βG83C assembles into an oligomeric structure the size of a dimer of tetramers. The oligomer has carbon monoxide‐binding properties similar to those of natural human hemoglobin. Unlike HbA,...

Abstract We present here a simple approach to identify domain boundaries in proteins of an unknown three‐dimensional structure. Our method is based on the hypothesis that a high‐side chain entropy of a region in a protein chain must be compensated by a high‐residue interaction energy within the region, which could correlate with a well‐structured part of the globule, that is, with a domain unit. For protein domains, this means that...

Abstract The aggregation and fibrillation of α‐synuclein has been implicated as a causative factor in Parkinson's disease and several other neurodegenerative disorders known as synucleinopathies. The effect of different factors on the process of fibril formation has been intensively studied in vitro. We show here that α‐synuclein interacts with different unstructured polycations (spermine, polylysine, polyarginine, and...

Abstract Protein aggregation is commonly observed during protein refolding. To better understand this phenomenon, the intermolecular interactions experienced by a protein during unfolding and refolding are inferred from second virial coefficient (SVC) measurements. It is accepted that a negative SVC is indicative of protein–protein interactions that are attractive, whereas a positive SVC indicates net repulsive interactions....

Abstract It has been established in a number of studies that the alkaline‐denatured state of pepsin (the IP state) is composed of a compact C‐terminal lobe and a largely unstructured N‐terminal lobe. In the present study, we have investigated the residual structure in the IP state in more detail, using limited proteolysis to isolate and characterize a tightly folded core region from this partially denatured pepsin. The isolated core region...

Abstract Nondenaturing electrospray mass spectrometry (ESI‐MS) has been used to reveal the presence of potential ligands in the ligand‐binding domain (LBD) of orphan nuclear receptors. This new approach, based on supramolecular mass spectrometry, allowed the detection and identification of fortuitous ligands for the retinoic acid‐related orphan receptor β (RORβ) and the ultraspiracle protein (USP). These fortuitous ligands were...

Abstract Single‐chain variable fragments (scFvs) of anti‐Lewisy hu3S193 humanized antibody were constructed by joining the VH and VL domains with either +2 residues, +1 residue, or by directly linking the domains. In addition two constructs were synthesized in which one or two C‐terminal residues of the VH domain were removed (−1 residue, −2 residue) and then joined directly to the VL domain. An scFv construct in the reverse orientation with the VL joined...

Abstract In the postgenomic era, the transformation of genetic information into biochemical meaning is required. We have analyzed the proteome of the chloroplast outer envelope membrane by an in silico and a proteomic approach. Based on its evolutionary relation to the outer membrane of Gram‐negative bacteria, the outer envelope membrane should contain a large number of β‐barrel proteins. We therefore calculated the probability for...

Abstract Hyperthermophilic archaea have an unusual phosphatase that exhibits activity toward both inositol‐1‐phosphate and fructose‐1,6‐bisphosphate, activities carried out by separate gene products in eukaryotes and bacteria. The structures of phosphatases from Archaeoglobus fulgidus (AF2372) and Methanococcus jannaschii (MJ0109), both anaerobic organisms, resemble the dimeric unit of the tetrameric pig kidney fructose bisphosphatase (FBPase). ...

Abstract Insulin folds into a unique three‐dimensional structure stabilized by three disulfide bonds. Our previous work suggested that during in vitro refolding of a recombinant single‐chain insulin (PIP) there exists a critical folding intermediate containing the single disulfide A20–B19. However, the intermediate cannot be trapped during refolding because once this disulfide is formed, the remaining folding process is very quick....

Abstract The simplified SH3 domain sequence, FP1, obtained in phage display selection experiments has an amino acid composition that is 95% Ile, Lys, Glu, Ala, Gly. Here we use NMR to investigate the tertiary structure of FP1. We find that the overall topology of FP1 resembles that of the src SH3 domain, the hydrogen‐deuterium exchange and chemical shift perturbation profiles are similar to those of naturally occurring SH3 domains,...

Page:   1 2 Next