22 research outputs found
Apolipoprotein E epsilon 4 (APOE-Δ4) genotype is associated with decreased 6-month verbal memory performance after mild traumatic brain injury
Introduction: The apolipoprotein E (APOE) Δ4 allele associates with memory impairment in neurodegenerative diseases. Its association with memory after mild traumatic brain injury (mTBI) is unclear. Methods: mTBI patients (Glasgow Coma Scale score 13â15, no neurosurgical intervention, extracranial Abbreviated Injury Scale score â€1) aged â„18 years with APOE genotyping results were extracted from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study. Cohorts determined by APOE-Δ4(+/â) were assessed for associations with 6-month verbal memory, measured by California Verbal Learning Test, Second Edition (CVLT-II) subscales: Immediate Recall Trials 1â5 (IRT), Short-Delay Free Recall (SDFR), Short-Delay Cued Recall (SDCR), Long-Delay F
DNA-binding proteins as site-specific nucleases
Summary
DNAâbinding proteins can be converted into siteâspecific nucleases by linking them to the chemical nuclease 1,10âphenanthrolineâcopper. This can be readily accomplished by converting a minor grooveâproximal amino acid to a cysteine residue using siteâdirected mutagenesis and then chemically modifying the sulphydryl group with 5âiodoacetamidoâ1,10â phenanthrolineâcopper. These chimeric scission reagents can be used as rare cutters to analyse chromosomal DNA, to test predictions based on highâresolution nuclear magnetic resonance and Xâray crystal structures, and to locate binding sites of proteins within genomes
The Production and Characterization of Artificial Heterodimers of the Restriction Endonuclease EcoRV
Dissecting the fine details of assembly of a T=3 capsid
The RNA bacteriophages represent ideal model systems in which to probe the detailed assembly pathway for the formation of a T?=?3 quasi-equivalent capsid. For MS2, the assembly reaction can be probed in vitro using acid disassembled coat protein subunits and a short (19 nt) RNA stem-loop that acts as the translational operator of the replicase gene and leads to sequence-specific sequestration and packaging of the cognate phage RNA in vivo. Reassembly reactions can be initiated by mixing these components at neutral pH. The molecular basis of the sequence-specific RNAâprotein interaction is now well understood. Recent NMR studies on the protein demonstrate extensive mobility in the loops of the polypeptide that alter their conformations to form the quasi-equivalent conformers of the final capsid. It seems reasonable to assume that RNA binding results in reduction of this flexibility. However, mass spectrometry suggests that these RNAâprotein complexes may only provide one type of quasi-equivalent capsid building block competent to form five-fold axes but not the full shell. Work with longer RNAs suggests that the RNA may actively template the assembly pathway providing a partial explanation of how conformers are selected in the growing shell