1,726,626 research outputs found
Evidence of interaction of phage P22 tailspike protein with DnaJ during translational folding
No full textPhage P22 tailspike is a thermostable homotrimeric protein, and temperature-sensitive folding (tsf) and global suppressor mutations affect its folding yields at elevated temperatures. We earlier suggested that the folding of the tailspike protein in Escherichia coli requires an unidentified molecular chaperone. Accordingly, in the present study, the interactions of purified DnaK, DnaJ, and GrpE heat-shock proteins with the tailspike protein were investigated during the translation and folding of the protein. The cotranslational addition of DnaJ to the tailspike protein resulted in the arrest of folding, when Dnak and GrpE were missing. However, the presence of DnaK, DnaJ, and GrpE had no effect on the folding yield of the tailspike protein, thus, providing evidence for the binding of the nascent tailspike protein with DnaJ protein, a member of DnaK chaperoning cycle.open
Side-chain specificity at three temperature-sensitive folding mutation sites of P22 tailspike protein
No full textThe phage P22 tailspike protein is one of the few proteins for which both in vivo and in vitro folding pathways have been thoroughly characterized. Many temperature-sensitive folding (tsf) mutations that cause the mutant tailspike polypeptides not to be folded at high restrictive temperatures have been identified. One-third of the tsf mutation sites are located in one domain called the dorsal fin domain (residues 197-259), which protrudes on the solvent-exposed side of the main β helix. In the present study, we introduced various amino acid substitutions at three tsf mutation sites (residue numbers 235, 238, and 244) in this domain to elucidate the mechanism of these tsf mutations in detail. The side-chain specificity at these tsf sites, together with structural examination in the tertiary fold, strongly suggests that destabilization of folding intermediates by loss of specific interactions is likely to be the major cause of the tsf defect in the dorsal fin domain.open
Effect of single amino acid substitutions on the thermal unfolding of P22 tailspike protein
No full textWe examined the thermal unfolding of four different mutant tailspike proteins of phage P22, which fold and mature more efficiently than the wild type. The mutations did not affect the unfolding of native protein to the intermediate conformation, but did affect the unfolding of intermediate to fully denatured monomer. For three mutations this process was more rapid than that for the wild type. The results suggest that the mutations which increa狀 the efficiency of folding and maturation of the tailspike in vivo do not necessarily decrease the thermal unfolding process of the native proteins in vitro.open
Correction: Development of a bio-electrospray system for cell and non-viral gene delivery
No full textCorrection for ‘Development of a bio-electrospray system for cell and non-viral gene delivery’ by Myung Chul Lee et al., RSC Adv., 2018, 8, 6452–6459.</p
sj-docx-1-tar-10.1177_17534666221144206 – Supplemental material for Cardiovascular and cerebrovascular–associated mortality in patients with preceding bronchiectasis exacerbation
No full textSupplemental material, sj-docx-1-tar-10.1177_17534666221144206 for Cardiovascular and cerebrovascular–associated mortality in patients with preceding bronchiectasis exacerbation by Sang Chul Lee, Kang Ju Son, Chang Hoon Han, Seon Cheol Park and Ji Ye Jung in Therapeutic Advances in Respiratory Disease</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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