temporary banners

 



 

Journal Issue - Volume 15 Issue 12 (December 2006)

  • When worlds colloid

  • Michael C. Wiener
  • Published in Wiley Interscience on Jan 01, 2009
  • DOI: 10.1110/ps.062559306 (p 2679-2681)

Abstract The interactions leading to crystallization of the integral membrane protein bacteriorhodopsin solubilized in n‐octyl‐β‐D‐glucoside were investigated. Osmotic second virial coefficients (B22) were measured by self‐interaction chromatography using a wide range of additives and precipitants, including polyethylene glycol (PEG) and heptane‐1,2,3‐triol (HT). In all cases, attractive protein–detergent complex (PDC) interactions were...

Abstract Dynamic processes are inherent properties of proteins and are crucial for a wide range of biological functions. To address how changes in protein sequence and structure affect dynamic processes, a quantitative comparison of microsecond‐to‐microsecond time scale conformational changes, measured by solution NMR spectroscopy, within homologous mesophilic and thermophilic ribonuclease H (RNase H) enzymes is presented. Kinetic...

Abstract In the brain, the extensively studied FAD‐dependent enzyme D‐amino acid oxidase (DAO) degrades the gliotransmitter D‐serine, a potent activator of N‐methyl‐D‐aspartate type glutamate receptors, and evidence suggests that DAO, together with its activator G72 protein, may play a key role in the pathophysiology of schizophrenia. Indeed, its potential clinical importance highlights the need for structural and functional...

Abstract This study describes an efficient multiparallel automated workflow of cloning, expression, purification, and crystallization of a large set of construct variants for isolated protein domains aimed at structure determination by X‐ray crystallography. This methodology is applied to MAPKAP kinase 2, a key enzyme in the inflammation pathway and thus an attractive drug target. The study reveals a distinct subset of truncation...

Abstract Hydantoin racemase enzyme plays a crucial role in the reaction cascade known as “hydantoinase process.” In conjunction with a stereoselective hydantoinase and a stereospecific carbamoylase, it allows the total conversion from D,L‐5‐monosubstituted hydantoins, with a low rate of racemization, to optically pure D‐ or L‐amino acids. Residues Cys76 and Cys181 belonging to hydantoin racemase from Sinorhizobium meliloti (SmeHyuA)...

Abstract Previous studies pointed to the importance of leucine residues in the binding of mitochondrial leader sequences to Tom20, an outer membrane protein translocator that initially binds the leader during import. A bacteria two‐hybrid assay was here employed to determine if this could be an alternative way to investigate the binding of leader to the receptor. Leucine to alanine and arginine to glutamine mutations were made in...

Abstract Six α‐defensins have been found in humans. These small arginine‐rich peptides play important roles in various processes related to host defense, being the effectors and regulators of innate immunity as well as enhancers of adoptive immune responses. Four defensins, called neutrophil peptides 1 through 4, are stored primarily in polymorphonuclear leukocytes. Major sites of expression of defensins 5 and 6 are Paneth cells of...

Abstract The SPRY domain was identified originally as a sequence repeat in the dual‐specificity kinase splA and ryanodine receptors and subsequently found in many other distinct proteins, including more than 70 encoded in the human genome. It is a subdomain of the B30.2/SPRY domain and is believed to function as a protein–protein interaction module. Three‐dimensional structures of several B30.2/SPRY domain–containing proteins have...

Abstract A critical evaluation of the performance of X‐ray refinement protocols using various energy functions is presented using the bovine pancreatic trypsin inhibitor (BPTI) protein. The four potential energy functions we explored include: (1) fully quantum mechanical calculations; (2) one based on an incomplete molecular mechanics (MM) energy function employed in the Crystallography and NMR System (CNS) with empirical parameters...

Abstract The creation of novel enzymes capable of catalyzing any desired chemical reaction is a grand challenge for computational protein design. Here we describe two new algorithms for enzyme design that employ hashing techniques to allow searching through large numbers of protein scaffolds for optimal catalytic site placement. We also describe an in silico benchmark, based on the recapitulation of the active sites of native...

Abstract The synucleins are a family of intrinsically disordered proteins involved in various human diseases. α‐Synuclein has been extensively characterized due to its role in Parkinson's disease where it forms intracellular aggregates, while γ‐synuclein is overexpressed in a majority of late‐stage breast cancers. Despite fairly strong sequence similarity between the amyloid‐forming regions of α‐ and γ‐synuclein, γ‐synuclein has...

Abstract Proteolytic degradation of basement membrane influences the cell behavior during important processes, such as inflammations, tumorigenesis, angiogenesis, and allergic diseases. In this study, we have investigated the action of gelatinase A (MMP‐2) on collagen IV, the major constituent of the basement membrane. We have compared quantitatively its action on the soluble forms of collagen IV extracted with or without pepsin...

Abstract Eosinophil cationic protein (ECP)/ribonuclease 3 is a member of the RNase A superfamily involved in inflammatory processes mediated by eosinophils. ECP is bactericidal, helminthotoxic, and cytotoxic to tracheal epithelium cells and to several mammalian cell lines although its RNase activity is low. We studied the thermal stability of ECP by fourth‐derivative UV absorbance spectra, circular dichroism, differential scanning...

Abstract Deletion of the regulatory N‐terminal arms of the AraC protein from its dimerization domain fragments increases the susceptibility of the dimerization domain to form a series of higher order polymers by indefinite self‐association. We investigated how the normal presence of the arm inhibits this self‐association. One possibility is that arms can act as an entropic bristles to interfere with the approach of other...

Page:   1 2 Next