Single-Molecule Studies of Cognate and Near-Cognate Elongation in an Eukaryotic Translation System.

The ribosome plays a central role in translation of the genetic code into amino acid sequences during synthesis of polypeptides. During each cycle of peptide elongation, the ribosome must discriminate between correct and incorrect aminoacyl-tRNAs according to the codon present in its A-site. Ribosomes rely on a complex sequence of proofreading mechanisms to minimize erroneous selection of incorrect aminoacyl-tRNAs that would lead to mistakes in translation.

Cytosolic and mitochondrial translation elongation are coordinated through the molecular chaperone TRAP1 for the synthesis and import of mitochondrial proteins.

A complex interplay between mRNA translation and cellular respiration has been recently unveiled, but its regulation in humans is poorly characterized in either health or disease. Cancer cells radically reshape both biosynthetic and bioenergetic pathways to sustain their aberrant growth rates. In this regard, we have shown that the molecular chaperone TRAP1 not only regulates the activity of respiratory complexes, behaving alternatively as an oncogene or a tumor suppressor, but also plays a concomitant moonlighting function in mRNA translation regulation.

Cytosolic and mitochondrial translation elongation are coordinated through the molecular chaperone TRAP1 for the synthesis and import of mitochondrial proteins.

A complex interplay between mRNA translation and cellular respiration has been recently unveiled, but its regulation in humans is poorly characterized in either health or disease. Cancer cells radically reshape both biosynthetic and bioenergetic pathways to sustain their aberrant growth rates. In this regard, we have shown that the molecular chaperone TRAP1 not only regulates the activity of respiratory complexes, behaving alternatively as an oncogene or a tumor suppressor, but also plays a concomitant moonlighting function in mRNA translation regulation.

Ataluren and aminoglycosides stimulate read-through of nonsense codons by orthogonal mechanisms.

During protein synthesis, nonsense mutations, resulting in premature stop codons (PSCs), produce truncated, inactive protein products. Such defective gene products give rise to many diseases, including cystic fibrosis, Duchenne muscular dystrophy (DMD), and some cancers. Small molecule nonsense suppressors, known as TRIDs (translational read-through-inducing drugs), stimulate stop codon read-through.

Kinetics of initiating polypeptide elongation in an IRES-dependent system.

The intergenic IRES of Cricket Paralysis Virus (CrPV-IRES) forms a tight complex with 80S ribosomes capable of initiating the cell-free synthesis of complete proteins in the absence of initiation factors. Such synthesis raises the question of what effect the necessary IRES dissociation from the tRNA binding sites, and ultimately from all of the ribosome, has on the rates of initial peptide elongation steps as nascent peptide is formed. Here we report the first results measuring rates of reaction for the initial cycles of IRES-dependent elongation.

Study of tert-Amyl Methyl Ether Low Temperature Oxidation Using Synchrotron Photoionization Mass Spectrometry.

This paper examines the oxidation reaction of tert-amyl methyl ether (TAME), an oxygenated fuel additive, with chlorine radical initiators in the presence of oxygen. Data are collected at 298, 550, and 700 K. Reaction intermediates and products are probed by a multiplexed chemical kinetics synchrotron photoionization mass spectrometer (SPIMS) and characterized on the basis of the mass-to-charge ratio, ionization energy, and photoionization spectra.

Composite pullulan-dextran polysaccharide scaffold with interfacial polyelectrolyte complexation fibers: a platform with enhanced cell interaction and spatial distribution.

Hydrogels are highly preferred in soft tissue engineering because they recapitulate the hydrated extracellular matrix. Naturally derived polysaccharides, like pullulan and dextran, are attractive materials with which to form hydrophilic polymeric networks due to their non-immunogenic and non-antigenic properties. However, their inherent hydrophilicity prevents adherent cell growth.

Synchrotron Photoionization Study of Mesitylene Oxidation Initiated by Reaction with Cl(P) or O(P) Radicals.

This work studies the oxidation of mesitylene (1,3,5-trimethylbenzene) initiated by O(P) or Cl(P) atoms. The O(P) initiated mesitylene oxidation was investigated at room temperature and 823 K, whereas the Cl-initiated reaction was carried out at room temperature only. Products were probed by a multiplexed chemical kinetics photoionization mass spectrometer using the synchrotron radiation produced at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory.

Low-temperature combustion chemistry of biofuels: pathways in the initial low-temperature (550 K-750 K) oxidation chemistry of isopentanol.

The branched C(5) alcohol isopentanol (3-methylbutan-1-ol) has shown promise as a potential biofuel both because of new advanced biochemical routes for its production and because of its combustion characteristics, in particular as a fuel for homogeneous-charge compression ignition (HCCI) or related strategies. In the present work, the fundamental autoignition chemistry of isopentanol is investigated by using the technique of pulsed-photolytic Cl-initiated oxidation and by analyzing the reacting mixture by time-resolved tunable synchrotron photoionization mass spectrometry in low-pressure (8 Torr) experiments in the 550-750 K temperature range. The mass-spectrometric experiments reveal a rich chemistry for the initial steps of isopentanol oxidation and give new insight into the low-temperature oxidation mechanism of medium-chain alcohols.