temporary banners

 



 

Journal Issue - Volume 17 Issue 9 (September 2008)

Abstract Human islet amyloid polypeptide (IAPP or amylin) is a 37‐residue hormone found as fibrillar deposits in pancreatic extracts of nearly all type II diabetics. Although the cellular toxicity of IAPP has been established, the structure of the fibrillar form found in these deposits is unknown. Here we have crystallized two segments from IAPP, which themselves form amyloid‐like fibrils. The atomic structures of these two...

Abstract A common objective in protein engineering is the enhancement of the thermodynamic properties of recombinant proteins for possible applications in nanobiotechnology. The performance of proteins can be improved by the rational design of chimeras that contain structural elements with the desired properties, thus resulting in a more effective exploitation of protein folds designed by nature. In this paper, we report the design...

Abstract Bacillus anthracis is well known in connection with biological warfare. The search for new drug targets and antibiotics is highly motivated because of upcoming multiresistant strains. Thymidylate kinase is an ideal target since this enzyme is at the junction of the de novo and salvage synthesis of dTTP, an essential precursor for DNA synthesis. Here the expression and characterization of thymidylate kinase from B. anthracis...

Abstract The identification of proteins present on the surface of Plasmodium falciparum‐infected red blood cells as well as of free merozoites has been widely considered as one of the main areas of research in the development of an antimalarial vaccine due to their involvement in the parasite's pathogenesis and invasion mechanisms. Major advances had been accomplished in this area thanks to the analysis of the reported genomic sequence of P....

Abstract It has been many years since position‐specific residue preference around the ends of a helix was revealed. However, all the existing secondary structure prediction methods did not exploit this preference feature, resulting in low accuracy in predicting the ends of secondary structures. In this study, we collected a relatively large data set consisting of 1860 high‐resolution, non‐homology proteins from the PDB, and further...

Abstract Streptococcus suis Dpr is an iron‐binding protein involved in oxidative stress resistance. It belongs to the bacterial Dps protein family whose members form dodecameric assemblies. Previous studies have shown that zinc and terbium inhibit iron incorporation in Listeria innocua Dps protein. In order to gain structural insights into the inhibitory effect of zinc and terbium, the crystal structures of Streptococcus suis Dpr complexes with...

Abstract Screening of transfer DNA (tDNA) tagged lines of Arabidopsis thaliana for mutants defective in systemic acquired resistance led to the characterization of dir1‐1 (defective in induced resistance [systemic acquired resistance, SAR]) mutant. It has been suggested that the protein encoded by the dir1 gene, i.e., DIR1, is involved in the long distance signaling associated with SAR. DIR1 displays the cysteine signature of lipid transfer...

Abstract The second WW domain in mammalian Salvador protein (SAV1 WW2) is quite atypical, as it forms a β‐clam‐like homodimer. The second WW domain in human MAGI1 (membrane associated guanylate kinase, WW and PDZ domain containing 1) (MAGI1 WW2) shares high sequence similarity with SAV1 WW2, suggesting comparable dimerization. However, an analytical ultracentrifugation study revealed that MAGI1 WW2 (Leu355–Pro390) chiefly exists as...

Abstract Isocitrate dehydrogenases (IDHs) catalyze oxidative decarboxylation of isocitrate (ICT) into α‐ketoglutarate (AKG). We report here the crystal structures of Saccharomyces cerevesiae mitochondrial NADP‐IDH Idp1p in binary complexes with coenzyme NADP, or substrate ICT, or product AKG, and in a quaternary complex with NADPH, AKG, and Ca2+, which represent different enzymatic states during the catalytic reaction. Analyses of these...

Abstract Protein aggregation is a hallmark of several neurodegenerative diseases and also of cataracts. The major proteins in the lens of the eye are crystallins, which accumulate throughout life and are extensively modified. Deamidation is the major modification in the lens during aging and cataracts. Among the crystallins, the βA3‐subunit has been found to have multiple sites of deamidation associated with the insoluble proteins...

Abstract In this paper, we introduce a fast and accurate side‐chain modeling method, named OPUS‐Rota. In a benchmark comparison with the methods SCWRL, NCN, LGA, SPRUCE, Rosetta, and SCAP, OPUS‐Rota is shown to be much faster than all the methods except SCWRL, which is comparably fast. In terms of overall χ1 and χ1+2 accuracies, however, OPUS‐Rota is 5.4 and 8.8 percentage points better, respectively, than SCWRL. Compared with NCN, which ...

Abstract SUMOylation, the covalent attachment of SUMO (small ubiquitin‐like modifier), is a eukaryotic post‐translational event that has been demonstrated to play a critical role in several biological processes. When used as an N‐terminal tag or fusion partner, SUMO has been shown to enhance functional protein production significantly by improving folding, solubility, and stability. We have engineered several SUMOs and, through...

Abstract The size of a protein is an important factor for understanding the sequence–structure relationship, and it affects both the amino acid composition and the residue burial of proteins. However, it is usually measured as the number of amino acids, although these effects would result from the reduction of surface regions relative to the volume of core regions in larger proteins. In addition, although these two effects are...

Abstract Nucleoside diphosphate kinase from Halomonas sp. 593 (HaNDK) exhibits halophilic characteristics. Residues 134 and 135 in the carboxy‐terminal region of HaNDK are Glu–Glu, while those of its homologous counterpart of non‐halophilic Pseudomonas NDK (PaNDK) are Ala–Ala. The double mutation, E134A‐E135A, in HaNDK results in the loss of the halophilic characteristics, and, conversely, the double mutation of A134E‐A135E in PaNDK confers...

Abstract Binding of the snake venom protein rhodocytin to CLEC‐2, a receptor on the surface of human platelets, initiates a signaling cascade leading to platelet activation and aggregation. We have previously solved the structure of CLEC‐2. The 2.4 Å resolution crystal structure of rhodocytin presented here demonstrates that it is the first snake venom or other C‐type lectin‐like protein to assemble as a non‐disulfide linked (αβ)2...

Page:   1 2 Next