A NOVEL PHENYLALANINE AMMONIA-LYASE FROM KANGIELLA KOREENSIS

This study describes cloning of the gene encoding a novel phenylalanine ammonia-lyase from Kangiella koreensis (KkPAL) into pET19b expression vector. Optimization of protein expression and purification conditions yielded 15 mg pure soluble protein from one liter of E.coli culture. Enzymatic activity measurements of the ammonia elimination reaction from different natural aromatic amino acids proved the protein to be a phenylalanine ammonia-lyase. The isolated protein showed remarkably high, 81.7 °C melting temperature, making it especially suitable for biocatalytic applications

Characterization of Yeast Strains with Ketoreductase Activity for Bioreduction of Ketones

This study describes six yeast strains for stereoselective ketone reductions. The reaction conditions for the yeast strains (Pichia carsonii, Lodderomyces elongisporus, Candida norvegica, Candida guillermondi, Debaromyces fabryi and Candida parapsilosis) were optimized in a design of experiments for three ketones of different properties. The pH tolerance, temperature stability and productivity of the bioreductions with lyophilized cells of the yeast strains were characterized. In several cases, the optimized bioreductions resulted in enantiopure alcohols (ee > 99 %) with conversions ranging from moderate to excellent

2-es típusú diabetesesek és nem cukorbetegek területen szerzett, belgyógyászati osztályos felvételt igénylő bakteriális infekcióinak klinikai összehasonlítása = Community-acquired bacterial infections among type 2 diabetic and non-diabetic patients hospitalized on a general medical ward: a clinical comparison

Absztrakt: Bevezetés: Korábban azt gondoltuk, hogy a bakteriális fertőzések cukorbetegségben gyakoribbak, súlyosabbak, nagyobb halálozással járnak, mint a nem cukorbetegek körében. Az újabb megfigyelések azonban ellentmondásosak. Célkitűzés: Prospektív, obszervációs vizsgálatunk célja az volt, hogy összehasonlítsuk 2-es típusú cukorbetegek (T2DM) és nem cukorbetegek (K) területen szerzett, belgyógyászati osztályos felvételt igénylő bakteriális infekcióit: 1) lokalizáció, 2) kórokozóspektrum, 3) 3 hónapos halálozás alapján. Módszer: Vizsgálatunkba konszekutív módon vontuk be a betegeket (T2DM: n = 205, K: n = 202). Jellemeztük a két csoport infekcióit, klinikai paramétereit, mortalitásukat, és összevetettük azokat a nemzetközi adatokkal. Eredmények: A glikémiát jellemző paramétereket és a BMI-t kivéve nem volt különbség a két csoport klinikai jellemzőiben. T2DM-ben a bőr- és lágyrész-fertőzés (37,1%), a K csoportban a légúti infekció volt a leggyakoribb (37,1%), melyeket a húgyúti infekciók követték (31,2%; 31,7%). A bőr- és lágyrész-infekció előfordulása T2DM-ben vizsgálatunkban meghaladja a nemzetközi adatokat (37,1% vs. 16%). T2DM-ben, a K csoporthoz viszonyítva, ezen infekciótípusban többször találtuk Gram-pozitív és Gram-negatív kórokozók együttes jelenlétét (23/76 vs. 5/46, p = 0,0149), a húgyúti fertőzésekben polimikrobás infekciókat (34,0% vs. 15,1%, p = 0,0335). Mortalitásbeli különbséget nem találtunk a két csoport között. T2DM-ben a bőr- és lágyrész-fertőzések, a nem cukorbetegeknél a légúti infekciók okozták a legtöbb halált. Következtetés: Területen szerzett, bakteriális infekció miatt belgyógyászati osztályra került 2-es típusú cukorbetegeinknél a nemzetközi adatokhoz képest nagyobb arányban találtunk bőr- és lágyrész-fertőzést; kórokozóként a leggyakrabban Gram-pozitív és Gram-negatív baktériumok együttes jelenlétét tudtuk kimutatni. Összességében nem találtunk különbséget a T2DM- és a nem cukorbeteg csoport között a 3 hónapos halálozásban. Eredményeink felhívják a figyelmet a primer prevenció fontosságára és hazai elégtelenségére a bőr- és lágyrész-fertőzés megelőzésében 2-es típusú cukorbetegségben. Orv Hetil. 2019; 160(41): 1623–1632. | Abstract: Introduction: Previous data showed bacterial infections among diabetic patients to be more serious and frequent, with higher mortality rates in comparison with non-diabetics. Recent investigations, however, are contradictory. Aim: The goal of our prospective, observational study was to compare patients hospitalized on a general medical ward due to community-acquired bacterial infections with type 2 diabetes mellitus (T2DM) to those of non-diabetics (K) by 1) infection localization, 2) spectrum of pathogens, 3) three-month mortality rates. Method: Patients were consecutively involved (T2DM: n = 205, K: n = 202). We characterized the infections, clinical parameters, mortalities of the two groups, and matched them to international data. Results: No difference regarding clinical details of the groups were found except for glycemic parameters and BMI. In the T2DM group the skin- and soft tissue- (37.1%), in the K patients respiratory infections (37.1%) were the most common, followed by urinary ones (31.2% and 31.7%, respectively). Skin- and soft tissue infection incidence among T2DM subjects were higher compared to international results (37.1% vs. 16%). Co-presence of Gram positive and Gram negative bacteria in the skin- and soft tissue infections (23/76 vs. 5/46, p = 0.0149), and polymicrobial origin in the urinary tract infections (34.0% vs. 15.1%, p = 0.0335) were found to be more frequent in T2DM than in K. No difference regarding mortality rates were detected. In T2DM the skin- and soft tissue while in the K group the respiratory infections had the most death counts. Conclusions: We found higher rates of skin- and soft tissue infections among T2DM patients hospitalized on a general medical ward compared to international data. In total we did not find difference regarding three-month mortality between the groups. Our results highlight the importance of primary prevention and shows its inadequacy concerning skin and soft tissue infections among type 2 diabetics in Hungary. Orv Hetil. 2019; 160(41): 1623–1632

Enantiocomplementary Bioreduction of 1-(Arylsulfanyl)propan-2-ones

This study explored the enantiocomplementary bioreduction of substituted 1-(arylsulfanyl)propan-2-ones in batch mode using four wild-type yeast strains and two different recombinant alcohol dehydrogenases from Lactobacillus kefir and Rhodococcus aetherivorans. The selected yeast strains and recombinant alcohol dehydrogenases as whole-cell biocatalysts resulted in the corresponding 1-(arylsulfanyl)propan-2-ols with moderate to excellent conversions (60–99%) and high selectivities (ee > 95%). The best bioreductions—in terms of conversion (>90%) and enantiomeric excess (>99% ee)—at preparative scale resulted in the expected chiral alcohols with similar conversion and selectivity to the screening reactions

Chemoenzymatic route to Tyrphostins involving lipase-catalyzed kinetic resolution of 1-phenylethanamine with alkyl cyanoacetates as novel acylating agents

Ethyl and isopropyl cyanoacetates were tested as acylating agents in the kinetic resolution of racemic 1-phenylethanamine rac-1 catalyzed by lipase B from Candida antarctica. The best conversion combined with high enantioselectivity was achieved with ethyl cyanoacetate 2a as the acylating agent and immobilized lipase B from Candida antarctica (CaLB N435) as the biocatalyst. Enantiomers of the amides (R)-3 and (S)-3 were obtained with high enantiopurity (ee >98%) by lipase-catalyzed kinetic resolution and by chemical conversion of the residual (S)-1, respectively. The amides were reacted with variousaromatic aldehydes 4a–c,e in Knoevenagel condensation to yield Tyrphostins rac-5a–c,e, (R)-5a–c,e and (S)-5a–c,e, which were tested as protein tyrosine kinase inhibitors on human cancer cell lines HCT 116, A549, PC9, PC9ER, Jurkat, and MV4-11. Although some of the novel Tyrphostins exhibited weak biological activities (EC50 6–60 lM), none of them proved to have a significant effect on the growth of the investigated cell lines

Characterization of Yeast Strains with Ketoreductase Activity for Bioreduction of Ketones

This study describes six yeast strains for stereoselective ketone reductions. The reaction conditions for the yeast strains (Pichia carsonii, Lodderomyces elongisporus, Candida norvegica, Candida guillermondi, Debaromyces fabryi and Candida parapsilosis) were optimized in a design of experiments for three ketones of different properties. The pH tolerance, temperature stability and productivity of the bioreductions with lyophilized cells of the yeast strains were characterized. In several cases, the optimized bioreductions resulted in enantiopure alcohols (ee &gt; 99 %) with conversions ranging from moderate to excellent.</jats:p

Immobilization of the Aspartate Ammonia-Lyase from Pseudomonas fluorescens R124 on Magnetic Nanoparticles: Characterization and Kinetics

Aspartate ammonia-lyases (AALs) catalyze the non-oxidative elimination of ammonia from l-aspartate to give fumarate and ammonia. In this work the AAL coding gene from Pseudomonas fluorescens R124 was identified, isolated, and cloned into the pET-15b expression vector and expressed in E. coli. The purified enzyme (PfAAL) showed optimal activity at pH 8.8, Michaelis-Menten kinetics in the ammonia elimination from l-aspartate, and no strong dependence on divalent metal ions for its activity. The purified PfAAL was covalently immobilized on epoxy-functionalized magnetic nanoparticles (MNP), and effective kinetics of the immobilized PfAAL-MNP was compared to the native solution form. Glycerol addition significantly enhanced the storability of PfAAL-MNP. Inhibiting effect of the growing viscosity (modulated by addition of glycerol or glucose) on the enzymatic activity was observed for the native and immobilized form of PfAAL, as previously described for other free enzymes. The storage stability and recyclability of PfAAL-MNP is promising for further biocatalytic applications. © 2022 The Authors. ChemBioChem published by Wiley-VCH Gmb