@article {2183, title = {Intraannular Savige-Fontana reaction: One-step conversion of one class of monocyclic peptides into another class of bicyclic peptides}, journal = {Chemistry-a European Journal}, volume = {14}, number = {11}, year = {2008}, note = {ISI Document Delivery No.: 291XITimes Cited: 1Cited Reference Count: 34May, Jonathan P. Perrin, David M.}, pages = {3404-3409}, type = {Article}, abstract = {Cyclisation and cross-linking strategies are important for the synthesis of cyclic and bicyclic peptides. These macrolactams are of great interest due to their increased biological activity compared to linear analogues. Herein, we describe the synthesis of a cyclic peptide containing an Hpi toxicophore, reminiscent of phakellistatins and omphalotins. The first intraannular cross-linking of such a peptide is then presented: using neat TFA to catalyse a Savige-Fontana tryptathionylation, the Hpi-containing peptide is converted to a bicyclic amatoxin analogue. As such, this methodology represents an efficient cyclisation method for cross-linking peptides and exposes a heretofore unrealised relationship between two different classes of peptide natural products. This finding increases the degree of potential chemical space for library generation.}, keywords = {2-CHLOROTRITYL CHLORIDE, 2-THIOETHER DERIVATIVES, amatoxin, ANALOGS, CROSS-LINKING, CYSTEINE SULFHYDRYL-GROUPS, ILE3-AMANINAMIDE, indole, ISOPHAKELLISTATIN-3, natural products, OXIDATION, PEPTIDES, PHALLOTOXINS, RNA POLYMERASE-II, TRYPTOPHAN}, isbn = {0947-6539}, url = {://000255230200019}, author = {May, J. P. and Perrin,David M.} } @article {2121, title = {Making connections for life: an in vivo map of the yeast interactome}, journal = {Hfsp Journal}, volume = {2}, number = {5}, year = {2008}, note = {ISI Document Delivery No.: 355VHTimes Cited: 1Cited Reference Count: 28Kast, Juergen}, month = {Oct}, pages = {244-250}, type = {Article}, abstract = {Proteins are the true workhorses of any cell. To carry out specific tasks, they frequently bind other molecules in their surroundings. Due to their structural complexity and flexibility, the most diverse array of interactions is seen with other proteins. The different geometries and affinities available for such interactions typically bestow specific functions on proteins. Having available a map of protein - protein interactions is therefore of enormous importance for any researcher interested in gaining insight into biological systems at the level of cells and organisms. In a recent report, a novel approach has been employed that relies on the spontaneous folding of complementary enzyme fragments fused to two different proteins to test whether these interact in their actual cellular context [Tarassov et al., Science 320, 1465-1470 (2008)]. Genome- wide application of this protein- fragment complementation assay has resulted in the first map of the in vivo interactome of Saccharomyces cerevisiae. The current data show striking similarities but also significant differences to those obtained using other large- scale approaches for the same task. This warrants a general discussion of the current state of affairs of protein - protein interaction studies and foreseeable future trends, highlighting their significance for a variety of applications and their potential to revolutionize our understanding of the architecture and dynamics of biological systems.}, keywords = {AMINO-ACIDS, CELL-CULTURE, COMPLEXES, CROSS-LINKING, IDENTIFICATION, MASS-SPECTROMETRY, PROTEIN-PROTEIN INTERACTIONS, QUANTIFICATION, QUANTITATION, SACCHAROMYCES-CEREVISIAE}, isbn = {1955-2068}, url = {://000259736700002}, author = {Kast, J.} } @article {2209, title = {Phosphorus-containing block copolymer templates can control the size and shape of gold nanostructures}, journal = {Journal of the American Chemical Society}, volume = {130}, number = {39}, year = {2008}, note = {ISI Document Delivery No.: 353GITimes Cited: 17Cited Reference Count: 31Noonan, Kevin J. T. Gillon, Bronwyn H. Cappello, Vittorio Gates, Derek P.}, month = {Oct}, pages = {12876-+}, type = {Article}, abstract = {{Amphiphilic block copolymers containing phosphine moieties in the main chain are employed as macromolecular ligands for gold (1). The sequential living anionic copolymerization of isoprene (1) and the phosphaalkene}, keywords = {ARCHITECTURE, CROSS-LINKING, DIBLOCK COPOLYMER, HOMOPOLYMERS, LIVING ANIONIC-POLYMERIZATION, micelles, MORPHOLOGIES, multiple, NANOPARTICLES, nanotechnology, POLYMERS}, isbn = {0002-7863}, url = {://000259553700020}, author = {Noonan, K. J. T. and Gillon, B. H. and Cappello, V. and Gates, D. P.} } @article {2276, title = {Utility of formaldehyde cross-linking and mass spectrometry in the study of protein-protein interactions}, journal = {Journal of Mass Spectrometry}, volume = {43}, number = {6}, year = {2008}, note = {ISI Document Delivery No.: 319PPTimes Cited: 22Cited Reference Count: 54Sutherland, Brent W. Toews, Judy Kast, Juergen}, month = {Jun}, pages = {699-715}, type = {Article}, abstract = {For decades, formaldehyde has been routinely used to cross-link proteins in cells, tissue, and in some instances, even entire organisms. Due to its small size, formaldehyde can readily permeate cell walls and membranes, resulting in efficient cross-linking, i.e. the formation of covalent bonds between proteins, DNA, and other reactive molecules. Indeed, formaldehyde cross-linking is an instrumental component of many mainstream analytical/cell biology techniques including chromatin immunoprecipitation (ChIP) of protein-DNA complexes found in nuclei; immunohistological analysis of protein expression and localization within cells, tissues, and organs; and mass spectrometry (MS)-compatible silver-staining methodologies used to visualize low abundance proteins in polyacrylamide gels. However, despite its exquisite suitability for use in the analysis of protein environments within cells, formaldehyde has yet to be commonly employed in the directed analysis of protein-protein interactions and cellular networks. The general purpose of this article is to discuss recent advancements in the use of formaldehyde cross-linking in combination with MS-based methodologies. Key advantages and limitations to the use of formaldehyde over other cross-linkers and technologies currently used to study protein-protein interactions are highlighted, and formaldehyde-based experimental approaches that are proving very promising in their ability to accurately and efficiently identify novel protein-protein and multiprotein interaction complexes are presented. Copyright (c) 2008 John Wiley \& Sons, Ltd.}, keywords = {ANTIGEN-RETRIEVAL, CHROMATIN IMMUNOPRECIPITATION, COMPLEXES, CROSS-LINKING, FORMALDEHYDE, IDENTIFICATION, IMMUNOHISTOCHEMISTRY, INTERACTION NETWORKS, MASS SPECTROMETRY, PARAFFIN-EMBEDDED TISSUE, protein interactions, PROTEOMICS, review, SURFACE-TOPOLOGY, THROUGHPUT}, isbn = {1076-5174}, url = {://000257176400001}, author = {Sutherland, B. W. and Toews, J. and Kast, J.} } @article {4978, title = {Reaction of human myoglobin and H2O2 - Involvement of a thiyl radical produced at cysteine 110}, journal = {Journal of Biological Chemistry}, volume = {275}, number = {27}, year = {2000}, note = {ISI Document Delivery No.: 332QGTimes Cited: 55Cited Reference Count: 52}, month = {Jul}, pages = {20391-20398}, type = {Article}, abstract = {The human myoglobin (Mb) sequence is similar to other mammalian Mb sequences, except for a unique cysteine at position 110. Reaction of wild-type recombinant human Mb, the C110A variant of human Mb, or horse heart Mb with H2O2 (protein/H2O2 = 1:1.2 mol/mol) resulted in formation of tryptophan peroxyl (Trp-OO.) and tyrosine phenoxyl radicals as detected by EPR spectroscopy at 77 K. For wild-type human Mb, a second radical (g similar to 2.036) was detected after decay of Trp-OO. that was not observed for the C110A variant or horse heart Mb. When the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) was included in the reaction mixture at protein/DMPO ratios less than or equal to 1:10 mol/mol, a DMPO adduct exhibiting broad absorptions was detected. Hyperfine couplings of this radical indicated a DMPO-thiyl radical. Incubation of mild-type human Mb with thiol-blocking reagents prior to reaction with peroxide inhibited DMPO adduct formation, whereas at protein/DMPO ratios greater than or equal to 1:25 mol/mol, DMPO-tyrosyl radical adducts were detected. Mass spectrometry of wild-type human Mb following reaction with H2O2 demonstrated the formation of a homodimer (mass of 34,107 +/- 5 atomic mass units) sensitive to reducing conditions. The human Mb C110A variant afforded no dimer under identical conditions. Together, these data indicate that reaction of wild-type human Mb and H2O2 differs from the corresponding reaction of other myoglobin species by formation of thiyl radicals that lead to a homodimer through intermolecular disulfide bond formation.}, keywords = {ASCORBATE, CROSS-LINKING, enzyme catalysis, HEMOGLOBIN, HYDROGEN-PEROXIDE, LOW-DENSITY-LIPOPROTEIN, METMYOGLOBIN, OXIDATION, SPERM WHALE MYOGLOBIN, SPIN ADDUCTS}, isbn = {0021-9258}, url = {://000088084500025}, author = {Witting, P. K. and Douglas, D. J. and Mauk, A. G.} } @article {4500, title = {Design of proteins using rigid organic macrocycles as scaffolds}, journal = {Bioorganic \& Medicinal Chemistry}, volume = {7}, number = {1}, year = {1999}, note = {ISI Document Delivery No.: 173QETimes Cited: 21Cited Reference Count: 39}, month = {Jan}, pages = {23-27}, type = {Article}, abstract = {We have designed and synthesized new three-helix template-assembled synthetic proteins (TASPs) 1a-c. The template was the rigid cyclotribenzylene (CTB) macrocycle 2, which has C-3 symmetry. Thiol moieties on the CTB template were used to link cysteine-containing peptide strands 3a-c via disulfide bonds. With designed peptide strands of 15 and 18 residues in length, the structure of TASPs 1a-c were determined to be helical in water according to circular dichroism (CD) spectroscopy. The helicities of TASPs la-e were unchanged over large ranges of pH (2-12) and salt concentrations (0-2 M KCl). TASPs 1a-c were also extremely resistant to chemical denaturants: it requires a guanidine hydrochloride (GnHCl) concentration of 7.4 M for TASPs 1a-c to lose 50\% of their helicity. The major force for stabilization of TASPs 1a-c is the hydrophobic bundling of the helices. (C) 1999 Elsevier Science Ltd. All rights reserved.}, keywords = {4-HELIX BUNDLE PROTEIN, ASSEMBLED SYNTHETIC PROTEINS, CHEMOSELECTIVE LIGATION, CONSTRUCTION, CROSS-LINKING, CRYSTAL-STRUCTURE, cyclotribenzylene, de novo protein, DE-NOVO PROTEINS, HELICAL BUNDLES, HELICAL PROTEIN, PEPTIDE, TASP, TEMPLATE}, isbn = {0968-0896}, url = {://000078990600004}, author = {Causton, A. S. and Sherman, J. C.} }