The ghost of research past

Stochastic inhibitor release and binding from single-enzyme molecules

herry submitted, created time 1 year 3 weeks (www.pnas.org)

Inhibition kinetics of single-β-galactosidase molecules with the slow-binding inhibitor D-galactal have been characterized by segregating individual enzyme molecules in an array of 50,000 ultra small reaction containers and observing substrate turnover changes with fluorescence microscopy.

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Molecular imaging of membrane interfaces reveals mode of β-glucosidase activation by saposin C

stephen submitted, created time 1 year 3 weeks (www.pnas.org)

Acid β-glucosidase (GCase) is a soluble lysosomal enzyme responsible for the hydrolysis of glucose from glucosylceramide and requires activation by the small nonenzymatic protein saposin C (sapC) to gain access to the membrane-embedded glycosphingolipid substrate.

Submit comment | Blog It | Email It | Keywords: membrane β -glucosidase activation lysosomal enzyme

Herpes simplex virus-infected cell protein 0 blocks the silencing of viral DNA by dissociating histone deacetylases from the CoREST–REST complex

william submitted, created time 1 year 1 month (www.pnas.org)

A preeminent phenotype of the infected cell protein 0 (ICP0) of herpes simplex virus 1 (HSV-1) is that it acts as a promiscuous transactivator. In most cell lines exposed to ΔICP0 mutant virus at low ratios of virus per cell infection, α genes are expressed but the transition to β and γ gene expression does not ensue, but can be enhanced by inhibitors of histone deacetylases (HDACs).

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Grasses, litter, and their interaction affect microbial biomass and soil enzyme activity

gh0706 submitted, created time 1 year 4 months (www.sciencedirect.com)

Plant effects on ecosystem processes are mediated through plant–microbial interactions belowground and soil enzyme assays are commonly used to directly relate microbial activity to ecosystem processes. Live plants influence microbial biomass and activity via differences in rhizosphere processes and detrital inputs

Submit comment | Blog It | Email It | Keywords: Acid phosphatase β -Glucosidase C3 and C4 grasses Soil enzymes

β-Oxidation in fatty acid degradation and beyond

badboy submitted, created time 1 year 6 months (www.sciencedirect.com)

"The degradation of fatty acids in plants occurs primarily in the peroxisomes through the β-oxidation cycle. Enzymes that are involved in various aspects of β-oxidation have been identified recently and shown to act biochemically on a diversity of fatty acids and derivatives. Analysis of several mutants has revealed essential roles for β-oxidation in the breakdown of reserve triacylglycerols, seed development, seed germination and post-germinative growth before the establishment of photosynthesis

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Regulation of β-Adrenergic Receptor Signaling by S-Nitrosylation of G-Protein-Coupled Receptor Kinase 2

fiona submitted, created time 1 year 6 months (www.cell.com)

"β-adrenergic receptors (β-ARs), prototypic G-protein-coupled receptors (GPCRs), play a critical role in regulating numerous physiological processes. The GPCR kinases (GRKs) curtail G-protein signaling and target receptors for internalization. Nitric oxide (NO) and/or S-nitrosothiols (SNOs) can prevent the loss of β-AR signaling in vivo, but the molecular details are unknown."

Submit comment | Blog It | Email It | Keywords: β -adrenergic receptors G-protein-coupled receptors Nitric oxide

Murine osteoblasts regulate mesenchymal stem cells via WNT and cadherin pathways: mechanism depends on cell-cell contact mode

BIOBOSS submitted, created time 1 year 7 months (www3.interscience.wiley.com)

Osteoblasts (OSTs) are derived from mesenchymal stem cells (MSCs) and coexist in close proximity with MSCs in bone during development and remodelling. Interactions between these two cell types remain obscure.

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Adjacent Residues in the E1 Initiator β-Hairpin Define Different Roles of the β-Hairpin in Ori Melting, Helicase Loading, and Helicase Activity

claudia submitted, created time 1 year 7 months (www.molecule.org)

We have analyzed two residues in the helicase domain of the E1 initiator protein. These residues are part of a highly conserved structural motif, the β-hairpin, which is present in the helicase domain of all papovavirus initiator proteins. These proteins are unique in their ability to transition from local template melting activity to unwinding. We demonstrate that the β-hairpin has two functions. First, it is the tool used by the E1 double trimer (DT) to pry open and melt double-stranded DNA. Second, it is required for the unwinding activity of the hexameric E1 helicase

Submit comment | Blog It | Email It | Keywords: Ori Melting Helicase Loading Helicase Activity β -Hairpin