Targeting NOX2 via p47/phox-p22/phox Inhibition with Novel Triproline Mimetics.

On the basis of the knowledge that the proline-rich hot spot RPP region of P(151)PSNPPPRPP(160), an oligopeptide derived from the cytosolic portion of p22 (p22), binds to the single functional bis-SH3 domain of the regulatory protein p47 (p47), we designed a mimetic of the tripeptide based on NMR and X-ray crystallographic data for the p22(151-161) peptide PPSNRPPA with a peptide construct. Incorporation of the synthetic pseudo-triproline mimetic Pro-Pro-Cyp in a molecule derived from molecular modeling studies led to only a 7-fold diminution in activity in a surface plasmon resonance assay relative to the same molecule containing the natural Pro-Pro-Pro tripeptide. The alternative sequence corresponding to a Pro-Cyp-Pro insertion was inactive.

Structure of bacteriophage SPP1 head-to-tail connection reveals mechanism for viral DNA gating.

In many bacterial viruses and in certain animal viruses, the double-stranded DNA genome enters and exits the capsid through a portal gatekeeper. We report a pseudoatomic structure of a complete portal system. The bacteriophage SPP1 gatekeeper is composed of dodecamers of the portal protein gp6, the adaptor gp15, and the stopper gp16.

Exploring helical folding of oligoureas during chain elongation by high-resolution magic-angle-spinning (HRMAS) NMR spectroscopy.

The development of novel folding oligomers (foldamers) for biological and biomedical applications requires both precise structural information and appropriate methods to detect folding propensity. However, the synthesis and the systematic conformational investigation of large arrays of oligomers to determine the influence of factors, such as chain length, side chains, and surrounding environment, on secondary structure can be quite tedious. Herein, we show for 2.

The checkpoint Saccharomyces cerevisiae Rad9 protein contains a tandem tudor domain that recognizes DNA.

DNA damage checkpoints are signal transduction pathways that are activated after genotoxic insults to protect genomic integrity. At the site of DNA damage, 'mediator' proteins are in charge of recruiting 'signal transducers' to molecules 'sensing' the damage. Budding yeast Rad9, fission yeast Crb2 and metazoan 53BP1 are presented as mediators involved in the activation of checkpoint kinases.

Applications of variable-angle sample spinning experiments to the measurement of scaled residual dipolar couplings and 15N CSA in soluble proteins.

NMR spectra of ubiquitin in the presence of bicelles at a concentration of 32% w/v have been recorded at 700 MHz under sample spinning conditions at the magic angle (54.7 degrees ) and at an angle of 45.5 degrees .

DEUSS: a perdeuterated poly(oxyethylene)-based resin for improving HRMAS NMR studies of solid-supported molecules.

A novel resin called DEUSS (perdeuterated poly(oxyethylene)-based solid support) has been prepared by anionic polymerization of deuterated [D4]ethylene oxide, followed by cross-linking with deuterated epichlorohydrin. DEUSS can be suspended in a wide range of solvents including organic and aqueous solutions, in which it displays a high swelling capacity. As measured by proton HRMAS of the swollen polymer, the signal intensity of the oxyethylene protons is reduced by a factor of 110 relative to the corresponding nondeuterated poly(oxyethylene)poly(oxypropylene) (POEPOP) resin, thus facilitating detailed HRMAS NMR studies of covalently linked molecules.

Measurement of scaled residual dipolar couplings in proteins using variable-angle sample spinning.

NMR spectra of ubiquitin in the presence of bicelles at a concentration of 25% w/v have been recorded under sample spinning conditions for different angles of rotation. For an axis of rotation equal to the magic angle, the (1)H/(15)N HSQC recorded without any (1)H decoupling in the indirect dimension corresponds to the classical spectrum obtained on a protein in an isotropic solution and allows the measurement of scalar J-couplings (1) J (NH). For an angle of rotation smaller than the magic angle, the bicelles orient with their normal perpendicular to the spinning axis, whereas for an angle of rotation greater than the magic angle the bicelles orient with their normal along the spinning axis.

Conformational analysis by HRMAS NMR spectroscopy of resin-bound homo-peptides from C(alpha)-methyl-leucine.

A series of [L-(alphaMe)Leu]n (n = 1-5) homo-peptides have been covalently linked to Tentagel and POEPOP resins and submitted to a conformational study using HRMAS NMR spectroscopy. Whereas the mono- and dipeptide are mainly fully-extended, stable 3(10)-helical structures are formed beginning from the trimer.

Characterization of the 310-helix in model peptides by HRMAS NMR spectroscopy.

A tetra- and a hepta-homopeptide from the C(alpha)-tetrasubstituted Aib (alpha-aminoisobutyric acid) residue were covalently linked to the POEPOP resin by the fragment-condensation approach. The conformational preferences of the two model peptides were determined for the first time on a solid support by means of high-resolution magic angle spinning NMR spectroscopy. The results obtained indicate that the Aib homopeptides adopt a regular 3(10)-helical structure even when they are covalently bound to a polymeric matrix, and thus confirm the remarkable conformational stability of the peptides rich in this amino acid.