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Journal Issue - Volume 8 Issue 10 (1999)

Abstract Mechanosensation in bacteria involves transducing membrane stress into an electrochemical response. In Escherichia coli and other bacteria, this function is carried out by a number of proteins including MscL, the mechanosensitive channel of large conductance. MscL is the best characterized of all mechanosensitive channels. It has been the subject of numerous structural and functional investigations. The explosion in experimental data...

Abstract Although the three‐dimensional structure of the dimeric class 3 rat aldehyde dehydrogenase has recently been published (Liu ZJ et al., 1997, Nature Struct Biol 4:317–326), few mechanistic studies have been conducted on this isoenzyme. We have characterized the enzymatic properties of recombinant class 3 human stomach aldehyde dehydrogenase, which is very similar in amino acid sequence to the class 3 rat aldehyde...

Abstract The effect of the potential antidiabetic drug (‐)(S)‐3‐isopropyl 4‐(2‐chlorophenyl)‐1,4‐dihydro‐1‐ethyl‐2‐methyl‐pyridine‐3,5,6‐tricarboxylate (W1807) on the catalytic and structural properties of glycogen phosphorylase a has been studied. Glycogen phosphorylase (GP) is an allosteric enzyme whose activity is primarily controlled by reversible phosphorylation of Ser14 of the dephosphorylated enzyme (GPb, less active, predominantly...

Abstract The effect of pressure on amide 15N chemical shifts was studied in uniformly 15N‐labeled basic pancreatic trypsin inhibitor (BPTI) in 90%H2O/10%H2O, pH 4.6, by H‐15N heteronuclear correlation spectroscopy between 1 and 2,000 bar. Most 15N signals were low field shifted linearly and reversibly with pressure (0.468 ± 0.285 ppm/2 kbar), indicating that the entire polypeptide backbone structure is sensitive to pressure. A significant variation of...

Abstract The sterile alpha motif (SAM) is a protein interaction domain of around 70 amino acids present predominantly in the N‐ and C‐termini of more than 60 diverse proteins that participate in signal transduction and transcriptional repression. SAM domains have been shown to homo‐ and hetero‐oligomerize and to mediate specific protein‐protein interactions. A highly conserved subclass of SAM domains is present at the intracellular...

Abstract We have adopted nanoflow electrospray ionization mass spectrometry (ESI‐MS) and isothermal titration calorimetry (ITC) to probe the mechanism of peptide recognition by the SH2 domain from the Src family tyrosine kinase protein, Fyn. This domain is involved in the mediation of intracellular signal transduction pathways by interaction with proteins containing phosphorylated tyrosine (Y*) residues. The binding of tyrosyl...

Abstract Penicillin G acylase is an important enzyme in the commercial production of semisynthetic penicillins used to combat bacterial infections. Mutant strains of Providencia rettgeri were generated from wild‐type cultures subjected to nutritional selective pressure. One such mutant, Bro1, was able to use 6‐bromohexanamide as its sole nitrogen source. Penicillin acylase from the Bro1 strain exhibited an altered substrate specificity ...

Abstract Recent studies have pointed out the important role of local water structures in protein conformational stability. Here, we present an accurate and computationally effective way to estimate the free energy contribution of the simplest water structure motif–the water bridge. Based on the combination of empirical parameters for accessible protein surface area and the explicit consideration of all possible water bridges with...

Abstract The 3D structures of complexes between the hydroxynitrile lyase from Hevea brasiliensis (Hb‐HNL) and several substrate and/or inhibitor molecules, including trichloracetaldehyde, hexafluoracetone, acetone, and rhodanide, were determined by X‐ray crystallography. The complex with trichloracetaldehyde showed a covalent linkage between the protein and the inhibitor, which had apparently resulted from nucleophilic attack of the catalytic...

  • Active site specificity of plasmepsin II

  • Jennifer Westling, Patty Cipullo, Su‐Hwi Hung, Howard Saft, John B. Dame, Ben M. Dunn
  • Published in Wiley Interscience on Dec 31, 2008
  • DOI: 10.1110/ps.8.10.2001 (p 2001-2009)

Abstract Members of the aspartic proteinase family of enzymes have very similar three‐dimensional structures and catalytic mechanisms. Each, however, has unique substrate specificity. These distinctions arise from variations in amino acid residues that line the active site subsites and interact with the side chains of the amino acids of the peptides that bind to the active site. To understand the unique binding preferences of...

Abstract Short chain L‐3‐hydroxyacyl CoA dehydrogenase (SCHAD) is a soluble dimeric enzyme critical for oxidative metabolism of fatty acids. Its primary sequence has been reported to be conserved across numerous tissues and species with the notable exception of the pig heart homologue. Preliminary efforts to solve the crystal structure of the dimeric pig heart SCHAD suggested the unprecedented occurrence of three enzyme subunits...

Abstract The three N‐glycosylation sites of human heparin binding protein (HBP) have been mutated to produce a nonglycosylated HBP (ng‐HBP) mutant. ng‐HBP has been crystallized and tested for biological activity. Complete X‐ray data have been collected to 2.1 Å resolution, and the structure has been fully refined to an R‐factor of 18.4% (Rfree 27.7%). The ng‐HBP structure reveals that neither the secondary nor tertiary structure have changed...

Abstract A retinoic acid binding protein isolated from the lumen of the rat epididymis (ERABP) is a member of the lipocalin superfamily. ERABP binds both the all‐trans and 9‐cis isomers of retinoic acid, as well as the synthetic retinoid (E)‐4‐[2‐(5,6,7,8)‐tetrahydro‐5,5,8,8‐tetramethyl‐2 napthalenyl‐1 propenyl]‐benzoic acid (TTNPB), a structural analog of all‐trans retinoic acid. The structure of ERABP with a mixture of all‐trans...

Abstract Unlike most protein crystals, form IX of bovine pancreatic ribonuclease A diffracts well when severely dehydrated. Crystal structures have been solved after 2.5 and 4 days of desiccation with CaSO4, at 1.9 and 2.0 Å resolution, respectively. The two desiccated structures are very similar. An RMS displacement of 1.6 Å is observed for main‐chain atoms in each structure when compared to the hydrated crystal structure with some large...

Abstract Eotaxin is a member of the chemokine family of about 40 proteins that induce cell migration. Eotaxin binds the CC chemokine receptor CCR3 that is highly expressed by eosinophils, and it is considered important in the pathology of chronic respiratory disorders such as asthma. The high resolution structure of eotaxin is known. The 74 amino acid protein has two disulfide bridges and shows a typical chemokine fold comprised of...

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