p-aminobenzoate N-oxygenase (AurF) from Streptomyces thioluteus catalyzes the formation of unusual polyketide synthase starter unit p-nitrobenzoic acid (pNBA) from p-aminobenzoic acid (pABA) in the biosynthesis of antibiotic aureothin. AurF is a metalloenzyme, but its native enzymatic activity has not been demonstrated in vitro, and its catalytic mechanism is unclear. In addition, the nature of the cofactor remains a controversy. Here, we report the in vitro reconstitution of the AurF enzyme activity, the crystal structure of AurF in the oxidized state, and the cocrystal structure of AurF with its product pNBA. Our combined biochemical and structural analysis unequivocally indicates that AurF is a non-heme di-iron monooxygenase that catalyzes sequential oxidation of aminoarenes to nitroarenes via hydroxylamine and nitroso intermediates.di-iron enzymes ͉ metalloenzymes ͉ N-oxygenation ͉ reaction mechanism

Background-The risks and benefits of long-term dual antiplatelet therapy remain unclear. Methods and Results-This prospective, multicenter, open-label, randomized comparison trial was conducted in 24 clinicalcenters in Korea. In total, 5045 patients who received drug-eluting stents and were free of major adverse cardiovascular events and major bleeding for at least 12 months after stent placement were enrolled between July 2007 and July 2011.Patients were randomized to receive aspirin alone (n=2514) or clopidogrel plus aspirin (n=2531 Continuing medical education (CME) credit is available for this article. Go to http://cme.ahajournals.org to take the quiz.

The cycle life and capacity fading mechanisms of secondary sulfur electrodes prepared by two different electrode fabrication methods were studied in an effort to improve the energy density of the cathode. Cycle life improved substantially when the uniformity of carbon distribution around the sulfur particles improved and electrode density increased, improving the overall structural integrity of the carbon matrix. Capacity fading in a high-energy-density cathode is mainly due to structural failure by physical crack propagations of the electrode structure and subsequent formation of the electrochemically irreversible Li 2 S layer at cracked surfaces of carbon particles or masses. The capacity fading due to these mechanisms appears to be reduced substantially and significantly by improved structural integrity with uniform pore structure of the carbon matrix. A Li/S cell containing a cathode fabricated by the improved technique cycled over 400 cycles without any severe structural damage of the electrode structure.

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ApoC-III is a 79 amino acid glycoprotein synthesized principally in the liver and associated with apoB-containing lipoproteins and HDL ( 1 ). apoC-III plays a key role in determining serum triglyceride levels and is a potent inhibitor of both the LPL-dependent and -independent pathways of triglyceride-rich lipoprotein (TRL) clearance. Thus, apoC-III inhibits the apoC-II-mediated activation of LPL and also inhibits hepatic lipase that plays an important role in the conversion of dense VLDL to IDL. Furthermore, apoC-III also inhibits TRL clearance by inhibiting receptor-mediated uptake of TRL by the liver ( 2 ).Recent work has shown that the CVD risk of circulating plasma apoC-III is not uniform, but rather dependent on its association with specifi c lipoproteins ( 3-5 ). This suggests that the effect of both LDL and HDL on CVD risk is context-dependent on the presence or absence of apoC-III. However, current methods to detect apoC-III on LDL or HDL utilize labor-intensive immunoprecipitation of apoC-III and/or ultracentrifugation methods that can only be Abstract Elevated apoC-III levels predict increased cardiovascular risk when present on LDL and HDL particles. We developed novel high-throughput chemiluminescent ELISAs that capture apoB, lipoprotein (a) [Lp(a)], and apoA-I in plasma and then detect apoC-III on these individual lipoproteins as apoCIII-apoB, apoCIII-Lp(a), and apoCIIIapoAI complexes, respectively. We assessed the effects on these complexes of placebo or 100-300 mg volanesorsen, a generation 2.0+ antisense drug that targets apoC3 mRNA in patients with hypertriglyceridemia, including familial chylomicronemia syndrome (n = 3), volanesorsen monotherapy (n = 51), and as add-on to fi brate (n = 26), treated for 85 days and followed for 176 days. Compared with placebo, volanesorsen was associated with an 82.3 ± 11.7%, 81.3 ± 15.7%, and 80.8 ± 13.6% reduction in apoCIII-apoB, apo-CIII-Lp(a), and apoCIII-apoA-I, respectively (300 mg dose; P < 0.001 for all), at day 92. Strong correlations in all assay measures were noted with total plasma apoC-III, chylomicron-apoC-III, and VLDL-apoC-III. In conclusion, novel high-throughput ELISAs were developed to detect lipoprotein-associated apoC-III, including for the fi rst time on Lp(a). Volanesorsen uniformly lowers apoC-III on apoB-100, Lp(a), and apoA-I lipoproteins, and may be a potent agent to reduce triglycerides and cardiovascular risk mediated by apoC-III.

Misaminoacylation of 3,4‐dihydroxyphenylalanine (Dopa) molecules to tRNATyr by endogenous tyrosyl‐tRNA synthetase allowed the quantitative replacement of tyrosine residues with a yield of over 90 % by an in vivo residue‐specific incorporation strategy, to create, for the first time, engineered mussel adhesive proteins (MAPs) in Escherichia coli with a very high Dopa content, close to that of natural MAPs. The Dopa‐incorporated MAPs exhibited a superior surface adhesion and water resistance ability by assistance of Dopa‐mediated interactions including the oxidative Dopa cross‐linking, and furthermore, showed underwater adhesive properties comparable to those of natural MAPs. These results propose promising use of Dopa‐incorporated engineered MAPs as bioglues or adhesive hydrogels for practical underwater applications.

Our aim was to evaluate the plaque characteristics of coronary arteries related to significant stenosis with coronary CT angiography (CCTA) and to discuss the diagnostic accuracy of CCTA in patients with high calcium scores. After institutional review board approval, 110 patients (63 men; mean age: 67.1 ± 7.9 years) with Agatston scores >400 were retrospectively reviewed. Patients underwent Agatston calcium scoring and 64-slice CCTA, in addition to invasive coronary angiography (CAG). The composition (calcified, mixed, and non-calcified) and configuration (concentric, eccentric) of coronary artery plaques were analyzed on a per-segment basis by CCTA. We analyzed the differences in plaque composition and configuration between significant (≥ 50%) and non-significant (<50%) stenosis. Additionally, the diagnostic accuracy of stenosis according to plaque composition was evaluated by CCTA, using CAG as a reference method. Significant differences in plaque composition and configurations were observed between the two groups. In cases of significant stenosis, the proportions of concentric, mixed, and non-calcified plaques were significantly higher than those of eccentric and calcified plaques (P < 0.001). The sensitivity and positive predictive value of mixed (97.4, 87.6%) and non-calcified plaques (97.8, 95.7%) were significantly higher than those of calcified plaques (87.6, 67.2%). Although CCTA has limited value due to low diagnostic accuracy of calcified plaques, knowledge about the high frequencies of mixed and non-calcified plaques in significant stenosis help to make an accurate assessment of CAD with CCTA in patients with high calcium scores.

BackgroundA low level of high-density lipoprotein cholesterol (HDL-C) is strongly associated with cardiovascular events. However, the significance of HDL-C after statin therapy on the outcome of patients who have undergone percutaneous coronary intervention (PCI) with drug eluting stents (DES) is unclear.ObjectivesTo investigate the significance of HDL-C after statin therapy on cardiovascular events in patients with coronary artery disease after DES implantation.MethodsPatients who underwent PCI with DES from January 2004 to December 2009 were prospectively enrolled. The follow-up lipid panel of 2693 patients (median lab follow-up duration 225 days) who had continued using statins after PCI and who attained low-density lipoprotein cholesterol (LDL-C) <100 mg/dl was analysed. Major adverse cardiac events (MACE), including all-cause death, non-fatal myocardial infarction, and target vessel revascularisation according to follow-up HDL-C level (40 mg/dl for men or 50 mg/dl for women) were compared with the use of propensity scores matching.ResultsMedian follow-up duration was 832 days. 1585 (58.9%) patients had low follow-up HDL-C and 1108 had high follow-up HDL-C. The low follow-up HDL-C group had significantly higher rates of MACE. Low follow-up HDL-C was a significant independent predictor of MACE (adjusted HR 1.404, 95% CI 1.111 to 1.774, p=0.004). In further analysis with propensity scores matching, overall findings were consistent.ConclusionsRaising HDL-C levels may be a subsequent goal after achieving target LDL-C levels in patients with DES implantation.