In Bacillus subtilis, the dl-endopeptidase LytE is responsible for lateral peptidoglycan hydrolysis during cell elongation. We found that σ(I)-dependent transcription of lytE is considerably enhanced in a strain with a mutation in ltaS, which encodes a major lipoteichoic acid (LTA) synthase. Similar enhancements were observed in mutants that affect the glycolipid anchor and wall teichoic acid (WTA) synthetic pathways. Immunofluorescence microscopy revealed that the LytE foci were considerably increased in these mutants. The localization patterns of LytE on the sidewalls appeared to be helix-like in LTA-defective or WTA-reduced cells and evenly distributed on WTA-depleted or -defective cell surfaces. These results strongly suggested that LTA and WTA affect both σ(I)-dependent expression and localization of LytE. Interestingly, increased LytE localization along the sidewall in the ltaS mutant largely occurred in an MreBH-independent manner. Moreover, we found that cell surface decorations with LTA and WTA are gradually reduced at increased culture temperatures and that LTA rather than WTA on the cell surface is reduced at high temperatures. In contrast, the amount of LytE on the cell surface gradually increased under heat stress conditions. Taken together, these results indicated that reductions in these anionic polymers at high temperatures might give rise to increases in SigI-dependent expression and cell surface localization of LytE at high temperatures.The bacterial cell wall is required for maintaining cell shape and bearing environmental stresses. The Gram-positive cell wall consists of mesh-like peptidoglycan and covalently linked wall teichoic acid and lipoteichoic acid polymers. It is important to determine if these anionic polymers are required for proliferation and environmental adaptation. Here, we demonstrated that these polymers affect the expression and localization of a peptidoglycan hydrolase LytE required for lateral cell wall elongation. Moreover, we found that cell surface decorations with teichoic acid polymers are substantially decreased at high temperatures and that the peptidoglycan hydrolase is consequently increased. These findings suggest that teichoic acid polymers control lateral peptidoglycan hydrolysis by LytE, and bacteria drastically change their cell wall content to adapt to their environment.
Abstract Dehydroamino acid (Dhaa) is recognized as a useful tool or substrate for amino acid and peptide research. Although the stereoselective synthesis of the thermodynamically more stable Z ‐Dhaa has been well examined and established, the stereoselective synthesis of E ‐Dhaa has still remained to be a challenging synthetic task. In this paper, a stereoselective synthesis of E ‐Dhaa esters using a new (α‐diphenylphosphono)glycine is described. The characteristic aspects of the new method are summarized as follows: (i) metal additives play an important role in the promotion of E ‐stereoselectivities. (ii) the use of NaI was effected for the synthesis of E ‐Dhaas bearing an aryl substituent and an amino functionality, (iii) MgBr 2 · OEt 2 and ZnCl 2 contributed to improve the E ‐stereoselective synthesis of E ‐Dhaas bearing an alkyl substituent and an oxygen functionality, (iv) various protecting and functional groups were compatible under the reaction conditions, and (v) N ‐Cbz, Boc, and acyl‐α‐(diphenylphosphono)glycines were served for the stereoselective olefination reaction to provide the corresponding E ‐Dhaas.
LEC mutant rats exhibit an abnormal hepatic copper accumulation, due to the defection of the rat homologue of the Wilson's disease gene. In this study, we found a definitive evidence that the rat Wilson's disease gene of LEC rats was partially deleted at the 3' end of its protein-coding region, by performing Southern blot analysis. Furthermore, in Northern blot analysis, we confirmed that expression of the rat Wilson's disease gene was deficient in the liver of LEC rats. The partial deletion of the rat Wilson's disease gene should be responsible for the deficient expression of that gene in LEC rats.
We report here a Japanese family with paramyotonia congenita. The proband was a 42-year-old woman (case 1), who noticed muscle stiffness and weakness in the cold since the age of 7 years. These symptoms were alleviated by warming. Her eldest son (case 2) also experienced similar symptoms, while her younger son and daughter were healthy. Neurological examination in case 1 revealed mild weakness in facial and neck muscles. Cold-induced muscle stiffness and weakness were present. Electromyography showed myotonic discharges, intensified by cooling or repetitive exercise. The amplitude of the compound muscle action potentials was also reduced by the repetitive exercise and cooling. Serum chemistry including potassium and CK was normal. Molecular analysis of SCN4A (exon22-24) by SSCP and nucleotide sequencing revealed a C-to-T transition at nucleotide 3,938, causing a substitution of 1313methionine of threonine in case 1. This mutation was confirmed by PCR-RFLP with a mismatched primer; the proband (case 1) and her eldest son (case 2) had a heterozygous mutation, while the other family members did not. This is the first report that a mutation in SCN4A was identified in a Japanese family with paramyotonia congenita.
The interrupted Passerini reaction of 3-(2-isocyanoethyl)-indole catalysed by 3,5,6-trifluoro-2-pyridone is described. The reaction diastereoselectively provided a tetracyclic furolindoline, which proved to be a good substrate for the Joullié-Ugi reaction; therefore, the sequential Passerini/Joullié-Ugi reactions were performed in one-pot to rapidly provide versatile and highly functionalised furoindolines from 3-(2-isocyanoethyl)-indole.
It is important to increase the iodine delivery rate (I), that is the iodine concentration of the contrast material (C) x the flow rate of the contrast material (Q), through microcatheters to obtain arteriograms of the highest contrast. It is known that C is an important factor that influences I. The purpose of this study is to establish a method of hydrodynamic calculation of the optimum iodine concentration (i.e., the iodine concentration at which I becomes maximum) of the contrast material and its flow rate through commercially available microcatheters. Iopamidol, ioversol and iohexol of ten iodine concentrations were used. Iodine delivery rates (I meas) of each contrast material through ten microcatheters were measured. The calculated iodine delivery rate (I cal) and calculated optimum iodine concentration (calculated C opt) were obtained with spreadsheet software. The agreement between I cal and I meas was studied by correlation and logarithmic Bland-Altman analyses. The value of the calculated C opt was within the optimum range of iodine concentrations (i.e. the range of iodine concentrations at which I meas becomes 90% or more of the maximum) in all cases. A good correlation between I cal and I meas (I cal = 1.08 I meas, r = 0.99) was observed. Logarithmic Bland-Altman analysis showed that the 95% confidence interval of I cal/I meas was between 0.82 and 1.29. In conclusion, hydrodynamic calculation with spreadsheet software is an accurate, generally applicable and cost-saving method to estimate the value of the optimum iodine concentration and its flow rate through microcatheters.
We have recently recognized errors in Table 1 and Fig. 2. Page 12873, Table 1, immunization and challenge schedule: In groups 1, 2 and 3, rBCG was primed at week 3, followed by booster immunization of rDIs at weeks 50 and 54.In groups 4 and 5, rDIs was primed at weeks 0 and 12, followed by booster immunization of rBCG at week 50.Then all animals were challenged with virulent SHIV KS661c at week 57.Page 12874, Fig. 2: The weeks after immunization shown on the x axis in panel A should read "3, 7, 11, 19, 27, 35, 50, 53, 54, and 56."The weeks after immunization shown on the x axis in panel B should read "0, 4, 8, 16, 24, 32, 50, 52, 53, 54, and 56."Although the patterns and magnitudes of the kinetics were almost the same as the original ones, the standard deviation of the ELISPOT data at the peak response at 54 weeks after immunization was 500, which was five times more than originally reported.Spot-forming cells were counted by using a KS ELISPOT system after 35 weeks of immunization.Before that, we counted SFCs using an inverted microscope.
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