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Interactions between poly α- L-glutamic acid (PGA) and metal ions Cd2+, Co2+ were studied by direct current polarography. The diffusion currents of these ions decreased sharply in the presence of PGA in the pH region from 5.0 through neutral. A corresponding increase in the helix content of the PGA–metal ion complex was revealed by CD measurements on the same solutions. Helix contents determined by polarography were in good agreement with those by CD in the neutral pH region. On the contrary, the decrease of current in lower acidic pH regions was independent of helix formation and suggested that metal ions coordinate to sporadically-dissociated carboxylate groups to cause aggregation of the intra and/or inter polymer chains. The diffusion current of the ions, therefore, is a parameter sensitive to the conformational changes of PGA from acidic through neutral pH region. [ABSTRACT FROM AUTHOR]

Background: Mutations in the nuclear envelope genes encoding LMNA and EMD are responsible for Emery-Dreifuss muscular dystrophy. However, LMNA mutations often manifest dilated cardiomyopathy with conduction disturbance without obvious skeletal myopathic complications. On the contrary, the phenotypic spectrums of EMD mutations are less clear. Our aims were to determine the prevalence of nonsyndromic forms of emerinopathy, which may underlie genetically undefined isolated cardiac conduction disturbance, and the etiology of thromboembolic complications associated with EMD mutations.Methods: Targeted exon sequencing was performed in 87 probands with familial sick sinus syndrome (n=36) and a progressive cardiac conduction defect (n=51).Results: We identified 3 X-linked recessive EMD mutations (start-loss, splicing, missense) in families with cardiac conduction disease. All 3 probands shared a common clinical phenotype of progressive atrial arrhythmias that ultimately resulted in atrial standstill associated with left ventricular noncompaction (LVNC), but they lacked early contractures and progressive muscle wasting and weakness characteristic of Emery-Dreifuss muscular dystrophy. Because the association of LVNC with EMD has never been reported, we further genetically screened 102 LVNC patients and found a frameshift EMD mutation in a boy with progressive atrial standstill and LVNC without complications of muscular dystrophy. All 6 male EMD mutation carriers of 4 families underwent pacemaker or defibrillator implantation, whereas 2 female carriers were asymptomatic. Notably, a strong family history of stroke observed in these families was probably due to the increased risk of thromboembolism attributable to both atrial standstill and LVNC.Conclusions: Cardiac emerinopathy is a novel nonsyndromic X-linked progressive atrial standstill associated with LVNC and increased risk of thromboembolism. [ABSTRACT FROM AUTHOR]

Fluoroquinolone antibiotics frequently found in environmental matrices (wastewater treatment plants, hospital wastewater, industrial wastewater and surface wastewater) causes potential threat to the environment. Enzymatic treatment for degradation of antibiotics from environmental matrices is a green and sustainable approach. Focusing on this, this study aimed to degrade two frequently found fluroquinolone emergent pollutants, ciprofloxacin and norfloxacin from wastewater. The trinuclear cluster of copper ions present in laccase has the ability to effectively remove organic micropollutants (OMPs). The uniqueness of this study is that it utilizes laccase enzyme extracted from spent mushroom waste (SMW) of P. florida for degradation of ciprofloxacin and norfloxacin and to achieve highest degradation efficiency various parameters were tweaked such as pH (3–6), temperature (30 °C and 50 °C), and ABTS (0.05, 0.6, and 1 mM) concentration. The results showed that the most effective degradation of ciprofloxacin (86.12–75.94%) and norfloxacin (83.27–65.94%) was achieved in 3 h at pH 4.5, temperature 30 °C, and 2,2′-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 0.05 mM concentration. Nevertheless, achieving degradation at 50 °C for both antibiotics, indicates thermostability nature of laccase (P. florida). Further, the fate of transformed products obtained from laccase mediated degradation was confirmed by liquid chromatography (LC-MS). Both the antibiotics undergo decarboxylation, depiperylyzation, dealkylation and defluorination as a result of laccase-mediated bond breakage. Anti-microbial activity of the biodegraded products was monitored by residual anti-bacterial toxicity test (E. coli and Staphylococcus aureus). The biodegraded products were found to be non-toxic and resulted in the growth of E. coli and Staphylococcus aureus , as determined by the agar-diffusion method. Moreover, the storage stability of laccase was determined for 28-day duration at varying pH (3–10) and temperature (4–50 °C). The maximum storage stability was obtained at pH 4.5 and temperature 30 °C. Therefore, utilizing SMW for the degradation of OMPs from wastewater not only benefits in degradation but also reuses SMW agro waste, shedding light on agro waste management. Thus, SMW is a one-pot solution for both OMPs biodegradation and circularity in the economy. [Display omitted] • Degradation of ciprofloxacin and norfloxacin was achieved in 3 h. • Degradation was achieved in: pH 4.5, temperature 30 °C and ABTS (0.05 mM). • Degradation pathway: piperazine ring removal, defluorination and decarboxylation. • EDG and EWG groups were the key factors to achieve degradation. [ABSTRACT FROM AUTHOR]