Polymeric Composite Materials for the Detection of Barium Ions in Aqueous Solutions

The design of polymeric composite materials (PCM) for the optical control of chemical substances is currently one of the actively developing fields of science “at the junction” of polymer, organic, and analytical chemistry. The purpose of this work is the preparation of PCM containing derivatives of crown ethers for the optical determination of barium ions. The polymeric composite materials containing a novel optical molecular sensor have been obtained and investigated on the basis of a number of film-forming polymers. The best results have been obtained for PCM based on polyvinyl butyral films (since the fluorescence and absorption maxima shifted by 9 and 16 nm, respectively) in the fluorescence and absorption spectra of this PCM in the presence of barium ions. This makes the proposed PCM highly promising as sensor elements for the detection of the barium ions in the aqueous solutions

Study of Catalytic Activity of Lipase and Lipase-Chitosan Complexes in Dynamics

Pancreatic porcine lipase (PPL) is the unique enzyme in numerous biochemical processes for human and animals. Stability in time is the critical point for many enzymes in relation to their further applications. The effect of chitosan on the activity of PPL during 2 months was investigated. Materials and Methods: Potentiometric method was used to study the catalytic activity of enzymes that based on measuring of the potential an electrode immersed in a triacetin (substrate) solution by titration with 0.01 M NaOH. A laboratory pH-stat with combined pH electrode was used for the measurements of this potential in the presence of PPL or PPL-chitosan complexes. Standard experimental conditions: 40 ºC, pH 7.0. Results: The following PPL activity values (data given in % to the activity of free lipase) vs. time (in 10 min. intervals) were obtained: 100%, 97.4%, 89.9%, 82.9%, 77.9% and 75.9% after 10, 20, 30, 40, 50 and 60 min., respectively. The PPL catalytic activity decreased at about ¼ to ½ of the initial values after 7 or 14 days, 1 or 2 months storage, although there were differences in the decline dynamics. The complex PPL:Chit=50:1 has better stabilizing properties as compared to other complexes; does not strongly inhibit lipase and requires a small amount of carrier (chitosan) for its formation. Conclusions: The complex PPL:Chit=25:1 is less effective as the PPL:Chit=50:1 complex, but both can be applicable in some industrial processes

Study of Catalytic Activity of Lipase and Lipase-Chitosan Complexes in Dynamics

Pancreatic porcine lipase (PPL) is the unique enzyme in numerous biochemical processes for human and animals. Stability in time is the critical point for many enzymes in relation to their further applications. The effect of chitosan on the activity of PPL during 2 months was investigated.Materials and Methods: Potentiometric method was used to study the catalytic activity of enzymes that based on measuring of the potential an electrode immersed in a triacetin (substrate) solution by titration with 0.01 M NaOH. A laboratory pH-stat with combined pH electrode was used for the measurements of this potential in the presence of PPL or PPL-chitosan complexes. Standard experimental conditions: 40 ºC, pH 7.0.Results: The following PPL activity values (data given in % to the activity of free lipase) vs. time (in 10 min. intervals) were obtained: 100%, 97.4%, 89.9%, 82.9%, 77.9% and 75.9% after 10, 20, 30, 40, 50 and 60 min., respectively. The PPL catalytic activity decreased at about ¼ to ½ of the initial values after 7 or 14 days, 1 or 2 months storage, although there were differences in the decline dynamics. The complex PPL:Chit=50:1 has better stabilizing properties as compared to other complexes; does not strongly inhibit lipase and requires a small amount of carrier (chitosan) for its formation.Conclusions: The complex PPL:Chit=25:1 is less effective as the PPL:Chit=50:1 complex, but both can be applicable in some industrial processes

Inflammation in Dry Eye Syndrome: Identification and Targeting of Oxylipin-Mediated Mechanisms

Dry eye syndrome (DES) is characterized by decreased tear production and stability, leading to desiccating stress, inflammation and corneal damage. DES treatment may involve targeting the contributing inflammatory pathways mediated by polyunsaturated fatty acids and their derivatives, oxylipins. Here, using an animal model of general anesthesia-induced DES, we addressed these pathways by characterizing inflammatory changes in tear lipidome, in correlation with pathophysiological and biochemical signs of the disease. The decline in tear production was associated with the infiltration of inflammatory cells in the corneal stroma, which manifested one to three days after anesthesia, accompanied by changes in tear antioxidants and cytokines, resulting in persistent damage to the corneal epithelium. The inflammatory response manifested in the tear fluid as a short-term increase in linoleic and alpha-linolenic acid-derived oxylipins, followed by elevation in arachidonic acid and its derivatives, leukotriene B4 (5-lipoxigenase product), 12-hydroxyeicosatetraenoic acid (12-lipoxigeanse product) and prostaglandins, D2, E2 and F2α (cyclooxygenase products) that was observed for up to 7 days. Given these data, DES was treated by a novel ophthalmic formulation containing a dimethyl sulfoxide-based solution of zileuton, an inhibitor of 5-lipoxigenase and arachidonic acid release. The therapy markedly improved the corneal state in DES by attenuating cytokine- and oxylipin-mediated inflammatory responses, without affecting tear production rates. Interestingly, the high efficacy of the proposed therapy resulted from the synergetic action of its components, namely, the general healing activity of dimethyl sulfoxide, suppressing prostaglandins and the more specific effect of zileuton, downregulating leukotriene B4 (inhibition of T-cell recruitment), as well as upregulating docosahexaenoic acid (activation of resolution pathways)

Genetically encodable bioluminescent system from fungi

Bioluminescence is found across the entire tree of life, conferring a spectacular set of visually oriented functions from attracting mates to scaring off predators. Half a dozen different luciferins, molecules that emit light when enzymatically oxidized, are known. However, just one biochemical pathway for luciferin biosynthesis has been described in full, which is found only in bacteria. Here, we report identification of the fungal luciferase and three other key enzymes that together form the biosynthetic cycle of the fungal luciferin from caffeic acid, a simple and widespread metabolite. Introduction of the identified genes into the genome of the yeast Pichia pastoris along with caffeic acid biosynthesis genes resulted in a strain that is autoluminescent in standard media. We analyzed evolution of the enzymes of the luciferin biosynthesis cycle and found that fungal bioluminescence emerged through a series of events that included two independent gene duplications. The retention of the duplicated enzymes of the luciferin pathway in nonluminescent fungi shows that the gene duplication was followed by functional sequence divergence of enzymes of at least one gene in the biosynthetic pathway and suggests that the evolution of fungal bioluminescence proceeded through several closely related stepping stone nonluminescent biochemical reactions with adaptive roles. The availability of a complete eukaryotic luciferin biosynthesis pathway provides several applications in biomedicine and bioengineering.This research was supported by Planta LLC and Evrogen JSC. IVIS imaging and animal experiments were carried out using the equipment of the Center for Collective Usage “Medical Nanobiotechologies” located in the Russian National Research Medical University. Experiments were partially carried out using the equipment provided by the Institute of Bioorganic Chemistry of the Russian Academy of Sciences Сore Facility (CKP IBCH; supported by Russian Ministry of Education and Science Grant RFMEFI62117X0018). T.G. and M.M.-H. acknowledge support from Spanish Ministry of Economy and Competitiveness Grant BFU2015-67107 cofounded by the European Regional Development Fund, European Research Council (ERC) Grant ERC-2012-StG-310325 under the European Union’s Seventh Framework Programme FP7/2007-2013, and the European Union’s Horizon 2020 Research and Innovation Programme under Marie Sklodowska-Curie Grant H2020-MSCA-ITN-2014-642095. F.A.K. acknowledges the support of HHMI International Early Career Scientist Program 55007424, the Spanish Ministry of Economy and Competitiveness (MINECO) Grants BFU2012-31329 and BFU2015-68723-P, MINECO Centro de Excelencia Severo Ochoa 2013-2017 Grant SEV-2012-0208, Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement de la Generalitat’s Agency for Management of University and Research Grants Program 2014 SGR 0974, the Centres de Recerca de Catalunya Programme of the Generalitat de Catalunya, and ERC Grant 335980_EinME under the European Union’s Seventh Framework Programme FP7/2007-2013. H.E.W., A.G.O., and C.V.S. acknowledge support from São Paulo Research Foundation Fundação de Amparo à Pesquisa do Estado de São Paulo Grants 11/10507-0 (to H.E.W.), 10/11578-5 (to A.G.O.), and 13/16885-1 (to C.V.S.)