The regulation of the branched chain alpha-keto acid dehydrogenase multienzyme complex was investigated in the isolated, perfused rat liver. The metabolic flux through the branched chain alpha-keto acid dehydrogenase was monitored by measuring the production of 14CO2 from infused 1-14C-labeled branched chain alpha-keto acid substrates. The rate of decarboxylation of alpha-keto[1-14C]isocaproate...

this research was conducted at the department of horticluture, university of tehran during years 2005-2006, to investigate the use of iran apatite rocks in zeoponic substrate and as well to evaluate them as substitutes for phosphate fertilizers. five different substrates namely: m1: 89 wt. % soil+10 wt. % zeolite + 1 wt.% jeyrood apatite; m2: 82 wt.% soil + 15 wt.% zeolite+ 3 wt. % jeyrood apat...

the application of conductive coatings on ferritic stainless steel can decrease electrical conductivity. theaim of this research was to investigate the electrical conductivity of cobalt coated aisi 430 ferritic stainlesssteel by pack cementation technique. coated coupons were analyzed using scanning electron microscopy(sem). electrical conductivity of the coated substrates was measured as a fun...

The enzyme-substrate complex is inherently transient, rendering its detection difficult. In our framework designed for bisubstrate systems-isotope-labeled, activity-based identification and tracking (IsoLAIT)-the common substrate, such as S-adenosyl-l-methionine (AdoMet) for methyltransferases, is replaced by an analogue (e.g., S-adenosyl-l-vinthionine) that, as a probe, creates a tightly bound...

The exosome complex of 3'-5' exonucleases participates in RNA maturation and quality control and can rapidly degrade RNA-protein complexes in vivo. However, the purified exosome showed weak in vitro activity, indicating that rapid RNA degradation requires activating cofactors. This work identifies a nuclear polyadenylation complex containing a known exosome cofactor, the RNA helicase Mtr4p; a p...

Recent studies of GroE-mediated protein folding indicate that substrate proteins are productively released from a cis ternary complex in which the nonnative substrate is sequestered within the GroEL channel underneath GroES. Here, we examine whether protein folding can occur in this space. Stopped-flow fluorescence anisotropy of a pyrene-rhodanese-GroEl complex indicates that addition of GroES ...

Translin and translin-associated factor-x are highly conserved in eukaroytes; they can form heteromeric complexes (known as C3POs) and participate in various nucleic acid metabolism pathways. In humans and Drosophila, C3POs cleave the fragmented siRNA passenger strands and facilitate the activation of RNA-induced silencing complex, the effector complex of RNA interference (RNAi). Here, we repor...

The Mre11/Rad50 complex is a central player in various genome maintenance pathways. Here, we report a novel mode of nuclease action found for the Escherichia coli Mre11/Rad50 complex, SbcC2/D2 complex (SbcCD). SbcCD cuts off the top of a cruciform DNA by making incisions on both strands and continues cleaving the dsDNA stem at ∼10-bp intervals. Using linear-shaped DNA substrates, we observed th...

Background Caldicellulosiruptor bescii is a thermophilic cellulolytic bacterium that efficiently deconstructs lignocellulosic biomass into sugars, which subsequently can be fermented into alcohols, such as ethanol, and other products. Deconstruction of complex substrates by C. bescii involves a myriad of highly abundant, substrate-specific extracellular solute binding proteins (ESBPs) and carbo...

BACKGROUND The von Hippel-Lindau (VHL) tumor suppressor gene encodes a component of a ubiquitin ligase complex, which is best understood as a negative regulator of hypoxia inducible factor (HIF). VHL ubiquitinates and degrades the α subunits of HIF, and this is proposed to suppress tumorigenesis and tumor angiogenesis. However, several lines of evidence suggest that there are unidentified subst...