Vía de las lectinas, una ruta del complemento en construcción / Lectin pathway, a complement route under construction

ntroducción: El sistema del complemento puede ser activado por tres vías: clásica, alternativa y de las lectinas, esta última en fase de estudio para su completamiento. Objetivo: Describir hasta donde se ha avanzado en la construcción de la vía de las lectinas, sus iniciadores, activadores, reguladores, cascada enzimática y sus funciones biológicas. Metodología: Se realizó una revisión sobre el tema en estudio empleando artículos de libre acceso en la base de datos Pubmed y los trabajos publicados por el grupo de trabajo de la Universidad de Goettigen, la Universidad de Aarhus en Dinamarca y el Laboratorio Central de Líquido Cefalorraquídeo (LABCEL) de la Universidad de Ciencias Médicas de La Habana en los últimos cinco años comprendidos en el período de enero de 2012 a marzo del 2017. Desarrollo: Los iniciadores de la vía de las lectinas son las moléculas de reconocimiento colectinas y ficolinas circulantes en sangre, que participan en muchos procesos del organismo. Los activadores de esta vía son las MASP 1, 2 presentes como proenzimas; y la MASP 3, MAp 19 y 44 actúan como reguladoras. La cascada enzimática luego del reconocimiento es similar a la ruta clásica. Conclusiones: Las colectinas y ficolinas inician la vía de las lectinas. Sus activadores son las MASP 1, 2. Los reguladores son la MASP-3, y las MAp 19 y 44. Similar a la clásica en su cascada enzimática. Es la más antigua en la filogenia por eso participa en muchos procesos en el organismo(AU)

Introduction. The complement system can be activated in three ways: classical, alternative and lectins, the latter in the study phase for its completion. Objective. To describe the progress made in the construction of the lectin pathway, its initiators, activators, regulators, enzymatic cascade and its biological functions. Methods. A review was made on the subject under study using articles of free access in the Pubmed database and the works published by the working group of the University of Goettigen, the University of Aarhus in Denmark and the Central Laboratory of Cefalorraquìdeo liquid (LABCEL) of the University of Medical Sciences of Havana in the last five years included in the period from January 2012 to March 2017. Development. The initiators of the lectin pathway are the collectin recognition molecules and circulating ficolins in blood, which participate in many processes of the organism. The activators of this pathway are MASP 1, 2 present as proenzymes; and MASP 3, MAp 19 and 44 act as regulators. The enzymatic cascade after recognition is similar to the classical route. Conclusions. Collectins and ficolines initiate the lectin pathway. Its activators are MASP 1, 2. The regulators are MASP-3, and MAp 19 and 44. Similar to the classic in its enzymatic cascade. It is the oldest in phylogeny so it participates in many processes in the body.(AU)

Characterization of biotechnologically relevant extracellular lipase produced by Aspergillus terreus NCFT 4269.10

Abstract Enzyme production by Aspergillus terreus NCFT 4269.10 was studied under liquid static surface and solid-state fermentation using mustard oil cake as a substrate. The maximum lipase biosynthesis was observed after incubation at 30 °C for 96 h. Among the domestic oils tested, the maximum lipase biosynthesis was achieved using palm oil. The crude lipase was purified 2.56-fold to electrophoretic homogeneity, with a yield of 8.44%, and the protein had a molecular weight of 46.3 kDa as determined by SDS-PAGE. Enzyme characterization confirmed that the purified lipase was most active at pH 6.0, temperature of 50 °C, and substrate concentration of 1.5%. The enzyme was thermostable at 60 °C for 1 h, and the optimum enzyme–substrate reaction time was 30 min. Sodium dodecyl sulfate and commercial detergents did not significantly affect lipase activity during 30-min incubation at 30 °C. Among the metal ions tested, the maximum lipase activity was attained in the presence of Zn2+, followed by Mg2+ and Fe2+. Lipase activity was not significantly affected in the presence of ethylenediaminetetraacetic acid, sodium lauryl sulfate and Triton X-100. Phenylmethylsulfonyl fluoride (1 mM) and the reducing, β-mercaptoethanol significantly inhibited lipase activity. The remarkable stability in the presence of detergents, additives, inhibitors and metal ions makes this lipase unique and a potential candidate for significant biotechnological exploitation.

A new alkalophilic isolate of Bacillus as a producer of cyclodextrin glycosyltransferase using cassava flour

Abstract Cyclodextrin glycosyltransferase (CGTase) catalyzes the conversion of starch into non-reducing cyclic sugars, cyclodextrins, which have several industrial applications. This study aimed to establish optimal culture conditions for β-CGTase production by Bacillus sp. SM-02, isolated from soil of cassava industries waste water lake. The optimization was performed by Central Composite Design (CCD) 2, using cassava flour and corn steep liquor as substrates. The maximum production of 1087.9 U mL−1 was obtained with 25.0 g L−1 of cassava flour and 3.5 g L−1 of corn steep after 72 h by submerged fermentation. The enzyme showed optimum activity at pH 5.0 and temperature 55 °C, and maintained thermal stability at 55 °C for 3 h. The enzymatic activity was stimulated in the presence of Mg+2, Ca+2, EDTA, K+, Ba+2 and Na+ and inhibited in the presence of Hg+2, Cu+2, Fe+2 and Zn+2. The results showed that Bacillus sp. SM-02 have good potential for β-CGTase production.

Interaction between CYP450 enzymes and metabolism of traditional Chinese medicine as well as enzyme activity assay / 中国中药杂志

Drugs are exogenous compounds for human bodies, and will be metabolized by many enzymes after administration. CYP450 enzyme, as a major metabolic enzyme, is an important phase I drug metabolizing enzyme. In human bodies, about 75% of drug metabolism is conducted by CYP450 enzymes, and CYP450 enzymes is the key factor for drug interactions between traditional Chinese medicine( TCM) -TCM, TCM-medicine and other drug combination. In order to make clear the interaction between metabolic enzymes and TCM metabolism, we generally chose the enzymatic activity as an evaluation index. That is to say, the enhancement or reduction of CYP450 enzyme activity was used to infer the inducing or inhibitory effect of active ingredients and extracts of traditional Chinese medicine on enzymes. At present, the common method for measuring metabolic enzyme activity is Cocktail probe drugs, and it is the key to select the suitable probe substrates. This is of great significance for study drug's absorption, distribution, metabolism and excretion (ADME) process in organisms. The study focuses on the interaction between TCMs, active ingredients, herbal extracts, cocktail probe substrates as well as CYP450 enzymes, in order to guide future studies.

Cambios en la actividad de algunas enzimas séricas en ratas con hipervitaminosis E / Changes in activity of some serum enzymes in rats with hypervitaminosis E

Poco se sabe sobre los cambios en la actividad de las enzimas séricas relacionadas con la función hepática durante la hipervitaminosis E. En el presente trabajo se estudió el efecto de la administración intraperitoneal de 50, 100, 200 y 400 mg de vitamina E/día, durante 20 días sobre la actividad enzimática sérica en 60 ratas Wistar machos, de 12 semanas de edad, con pesos entre 180 y 200 gramos. El grupo control estuvo integrado por 15 ratas Wistar sanas, con edad y peso similares a los animales tratados. Al final del estudio, se tomaron muestras de sangre para la determinación de la vitamina E y la actividad de las enzimas: alanina aminotransferasa (ALT), aspartato aminotransferasa (AST), α-amilasa (AMS), arginasa (ARG), fosfohexosaisomerasa (PHI), fosfatasa alcalina (ALP), γ-glutamiltransferasa (γ-GT) y 5´-nucleotidasa (5´-N). La administración de vitamina E en exceso incrementó de manera significativa (p<0,05) el contenido sérico de la vitamina E y la actividad de todas las enzimas valoradas (p< 0,05); mientras que la α-amilasa disminuyó (p< 0,05) al ser comparada con los controles no tratados. Nuestros resultados proporcionan evidencia que la administración a corto plazo de dosis altas de vitamina E, produce un incremento en la actividad de las enzimas marcadoras de daño hepático (como aminotransferasas, ARG y PHI) y de colestasis (como ALP, 5´-N y γ-GT), que se corresponde con la forma mixta de enfermedad hepática (daño+colestasis).

Little is known about the possible changes in blood enzyme activity related to liver function during hypervitaminosis E. In the present work the effects of intraperitoneal administration of 50, 100, 200 and 400 mg of vitamin E (α-tocopherol) daily for 20 days, respectively, on the serum enzyme activity in 60 white male Wistar rats, aged 12 weeks and weighing 180-200 g, were studied. The group control was integrated by 15 healthy rats with similar characteristics (age and weight) to treated animals. Excess of vitamin E produced a significant (p<0.05) increase in the serum content of vitamin E and in the activity (p<0.05) of the following enzymes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), arginase (ARG), phosphohexosaisomerase (PHI), alkaline phosphatase (ALP), γ-glutamyltransferase (γ-GT) and 5´-nucleotidase (5´-N) while α-amylase (AMS) decreased (p<0.05) on comparing with the control group. These changes depend on the doses given of vitamin E. In conclusion, our results provide evidence that short-term administration of high doses of vitamin E produces an increase in the activity of the enzymes marker of liver damage (as aminotransferases, ARG and PHI) and of cholestasis (as ALP, γ-GT and 5´-N) that correspond to the mixed form of liver disease (injury+cholestasis).

Cloning and characterization of newly isolated lipase from Enterobacter sp. Bn12

A mesophilic Enterobacter sp. Bn12 producing an alkaline thermostable lipase was isolated from soil in Tehran, Iran. The lipase gene (ELBn12) was identified from a genomic library. Sequence analysis of the DNA fragment revealed an open reading frame of 879 bp encoding a lipase with a molecular mass of 31.3 kDa. The deduced amino acid sequence showed 96% identity with a lipase of Enterobacter sp. Ag1 and the identity of their DNA sequences was 88.9%. ELBn12 belongs to the lipase subfamily I.1 and its catalytic triad consists of Ser82, Asp237 and His259. The lipase was expressed in Escherichia coli (BL21) pLysS and partially purified by anion exchange chromatography. The maximum activity of ELBn12 was obtained at temperature of 60 °C and pH 8.0 towards tricaprylin (C8) and its specific activity was around 2900 U/mg. ELBn12 was stable within a broad pH range from 6.0 to 11.0. The enzyme showed high stability in both polar and nonpolar organic solvents at 50% (v/v). The lipase activity was enhanced in the presence of 10 mM of Ca2+, Mg2+ and K+, while heavy metals (Fe3+ and Zn2+) had strong inhibitory effect. ELBn12 showed high activity in the presence of 1% (w/v) nonionic surfactants, however ionic surfactants inhibited the lipolytic activity. ELBn12 characteristics show that it has a potential to be used in various industrial processes.

Aflatoxin detoxification by manganese peroxidase purified from Pleurotus ostreatus

Manganese peroxidase (MnP) was produced from white rot edible mushroom Pleurotus ostreatus on the culture filtrate. The enzyme was purified to homogeneity using (NH4)2SO4 precipitation, DEAE-Sepharose and Sephadex G-100 column chromatography. The final enzyme activity achieved 81UmL-1, specific activity 78 U mg-1 with purification fold of 130 and recovery 1.2% of the crude enzyme. SDS-PAGE indicated that the pure enzyme have a molecular mass of approximately 42 kDa. The optimum pH was between 4-5 and the optimum temperature was 25 ºC. The pure MnP activity was enhanced by Mn2+,Cu2+,Ca2+ and K+ and inhibited by Hg+2 and Cd+2.H2O2 at 5 mM enhanced MnP activity while at 10 mM inhibited it significantly. The MnP-cDNA encoding gene was sequenced and determined (GenBank accession no. AB698450.1). The MnP-cDNA was found to consist of 497 bp in an Open Reading Frame (ORF) encoding 165 amino acids. MnP from P. ostreatus could detoxify aflatoxin B1 (AFB1) depending on enzyme concentration and incubation period. The highest detoxification power (90%) was observed after 48 h incubation at 1.5 U mL-1 enzyme activities.

The effect of 5-aminoimidazole-4-carboxamide-ribonucleoside was mediated by p38 mitogen activated protein kinase signaling pathway in FRO thyroid cancer cells

BACKGROUND/AIMS: 5'-Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a cellular energy sensor that monitors intracellular AMP/adenosine triphosphate (ATP) ratios and is a key regulator of the proliferation and survival of diverse malignant cell types. In the present study, we investigated the effect of activating AMPK by 5-aminoimidazole-4-carboxamide-ribonucleotide (AICAR) in thyroid cancer cells. METHODS: We used FRO thyroid cancer cells harboring the BRAF(V600E) mutation to examine the effect of AICAR on cell proliferation and cell survival. We also evaluated the involvement of mitogen-activated protein kinase (MAPK) pathways in this effect. RESULTS: We found that AICAR treatment promoted AMPK activation and suppressed cell proliferation and survival by inducing p21 accumulation and activating caspase-3. AICAR significantly induced activation of p38 MAPK, and pretreatment with SB203580, a specific inhibitor of the p38 MAPK pathway, partially but significantly rescued cell survival. Furthermore, small interfering RNA targeting AMPK-alpha1 abolished AICAR-induced activation of p38 MAPK, p21 accumulation, and activation of caspase-3. CONCLUSIONS: Our findings demonstrate that AMPK activation using AICAR inhibited cell proliferation and survival by activating p38 MAPK and proapoptotic molecules in FRO thyroid cancer cells. These results suggest that the AMPK and p38 MAPK signaling pathways may be useful therapeutic targets to treat thyroid cancer.

An oxidant and organic solvent tolerant alkaline lipase by P. aeruginosa mutant: downstream processing and biochemical characterization

An extracellular alkaline lipase from Pseudomonas aeruginosa mutant has been purified to homogeneity using acetone precipitation followed by anion exchange and gel filtration chromatography and resulted in 27-fold purification with 19.6% final recovery. SDS-PAGE study suggested that the purified lipase has an apparent molecular mass of 67 kDa. The optimum temperature and pH for the purified lipase were 45°C and 8.0, respectively. The enzyme showed considerable stability in pH range of 7.0-11.0 and temperature range 35-55 °C. The metal ions Ca2+, Mg2+ and Na+ tend to increase the enzyme activity, whereas, Fe2+ and Mn2+ ions resulted in discreet decrease in the activity. Divalent cations Ca+2 and Mg+2 seemed to protect the enzyme against thermal denaturation at high temperatures and in presence of Ca+2 (5 mM) the optimum temperature shifted from 45°C to 55°C. The purified lipase displayed significant stability in the presence of several hydrophilic and hydrophobic organic solvents (25%, v/v) up to 168 h. The pure enzyme preparation exhibited significant stability and compatibility with oxidizing agents and commercial detergents as it retained 40-70% of its original activities. The values of Km and Vmax for p-nitrophenyl palmitate (p-NPP) under optimal conditions were determined to be 2.0 mg.mL-1 and 5000 μg.mL-1.min-1, respectively.

Optimization and characterization of alkaline protease and carboxymethyl-cellulase produced by Bacillus pumillus grown on Ficus nitida wastes

The potentiality of 23 bacterial isolates to produce alkaline protease and carboxymethyl-cellulase (CMCase) on Ficus nitida wastes was investigated. Bacillus pumillus ATCC7061 was selected as the most potent bacterial strain for the production of both enzymes. It was found that the optimum production of protease and CMCase were recorded at 30 °C, 5% Ficus nitida leaves and incubation period of 72 h. The best nitrogen sources for protease and CMCase production were yeast extract and casein, respectively. Also maximum protease and CMCase production were reported at pH 9 and pH 10, respectively. The enzymes possessed a good stability over a pH range of 8-10, expressed their maximum activities at pH10 and temperature range of 30-50 °C, expressed their maximum activities at 50 °C. Ions of Hg2+, Fe2+ and Ag+ showed a stimulatory effect on protease activity and ions of Fe2+, Mg2+, Ca2+, Cu2+ and Ag+ caused enhancement of CMCase activity. The enzymes were stable not only towards the nonionic surfactants like Triton X-100 and Tween 80 but also the strong anionic surfactant, SDS. Moreover, the enzymes were not significantly inhibited by EDTA or cystein. Concerning biotechnological applications, the enzymes retained (51-97%) of their initial activities upon incubation in the presence of commercials detergents for 1 h. The potential use of the produced enzymes in the degradation of human hair and cotton fabric samples were also assessed.

Salicylic acid derivatives as simplified and novel GK small molecule activators / 药学学报

Glucokinase (GK) is a new target for the treatment of type II diabetes mellitus (T2DM). In order to find a structure-simplified small molecule GK activator, 19 salicylic acid derivatives were designed and synthesized based on new lead compound (1). Experimental results showed that the potency of compound 8h is superior to control RO-28-0450 in GK activation.

Ethanol fermentation of sugarcane molasses by Zymomonas mobilis MTCC 92 immobilized in Luffa cylindrica L. sponge discs and Ca-alginate matrices

Bio-ethanol production from cane molasses (diluted to 15 % sugar w/v) was studied using the bacterium, Zymomonas mobilis MTCC 92 entrapped in luffa (Luffa cylindrica L.) sponge discs and Ca-alginate gel beads as the immobilizing matrices. At the end of 96 h fermentation, the final ethanol concentrations were 58.7 ± 0.09 and 59.1 ± 0.08 g/l molasses with luffa and Ca-alginate entrapped Z. mobilis cells, respectively exhibiting 83.25 ± 0.03 and 84.6 ± 0.02 % sugar conversion. There was no statistical significant difference (Fischer's LSD) in sugar utilization (t = 0.254, p <0.801) and ethanol production (t =-0.663, p <0.513) between the two immobilization matrices used. Further, the immobilized cells in both the matrices were physiologically active for three more cycles of operation with less than 15 % decrease in ethanol yield in the 4th cycle, which was due to some leakage of cells. In conclusion, luffa sponge was found to be equally good as Ca-alginate as a carrier material for bacterial (Z. mobilis. cell immobilization for ethanol production. Further, it has added advantages such as it is cheap, non-corrosive and has no environmental hazard.

Screening and isolation of halophilic bacteria producing industrially important enzymes

Halophiles are excellent sources of enzymes that are not only salt stable but also can withstand and carry out reactions efficiently under extreme conditions. The aim of the study was to isolate and study the diversity among halophilic bacteria producing enzymes of industrial value. Screening of halophiles from various saline habitats of India led to isolation of 108 halophilic bacteria producing industrially important hydrolases (amylases, lipases and proteases). Characterization of 21 potential isolates by morphological, biochemical and 16S rRNA gene analysis found them related to Marinobacter, Virgibacillus, Halobacillus, Geomicrobium, Chromohalobacter, Oceanobacillus, Bacillus, Halomonas and Staphylococcus genera. They belonged to moderately halophilic group of bacteria exhibiting salt requirement in the range of 3-20%. There is significant diversity among halophiles from saline habitats of India. Preliminary characterization of crude hydrolases established them to be active and stable under more than one extreme condition of high salt, pH, temperature and presence of organic solvents. It is concluded that these halophilic isolates are not only diverse in phylogeny but also in their enzyme characteristics. Their enzymes may be potentially useful for catalysis under harsh operational conditions encountered in industrial processes. The solvent stability among halophilic enzymes seems a generic novel feature making them potentially useful in non-aqueous enzymology.

Characterization of pathogenic Aeromonas veronii bv. veronii associated with ulcerative syndrome from Chinese longsnout catfish (Leiocassis longirostris Günther)

273 bacterial strains were isolated from 20 Chinese longsnout catfish samples. The biochemical characteristics of all strains conformed to the species description of Aeromonas veronii bv. veronii on the basis of Vitek GNI+ card. Furthermore, 16S rDNA, gyrB and rpoD sequences of the representative strain PY50 were sequenced and showed high similarity with A. veronii bv. veronii in Genbank. Antibiotic-resistance of the representative strain PY50 was assessed by the Kirby-Bauer disk diffusion method, and the results showed it was susceptible and moderately susceptible to 13 and 4 of the 21 antimicrobial agents tested. Extracellular products of strain PY50 contained gelatinase, lecithinase, elastase, most of lipase and lipopolysaccharide. Virulence of strain PY50 and extracellular products to Chinese longsnout catfish were also tested, and LD50 were about 3.47~10(4) CFU per fish and 11.22 ƒÊg per fish in intraperitoneal injection respectively. This is the first report that A. veronii bv. veronii was the pathogenic agent of ulcerative syndrome in Chinese longsnout catfish.

Research progress of effect of anti-diabetic traditional Chinese medicines based on regulation of glucose metabolic enzyme / 中国中药杂志

Diabetes is a global threat threatening human health in the world, with an increasing incidence rate in recent years. The disorder of glucose metabolism is one of the major factors. As relevant glucose metabolic enzymes such as alpha-glucosidase, glucose-6-phosphatase (G-6-P), glycogen phosphorylase (GP) and glycogen synthase kinase-3 (GSK-3) get involved in and control the process of glucose metabolism, the regulation of the activity of glucose metabolic enzymes is of significance to the treatment of diabetes. Traditional Chinese medicines (TCMs) have been widely researched because of their low toxicology and high efficiency, and many extracts and components from TCMs have been proven to be regulators of glucose metabolic enzymes. Compared with anti-diabetic western medicines, anti-diabetic TCMs feature safety, reliability and low price. This essay summarizes the anti-diabetic effect of TCMs on regulating glucose metabolic enzymes.

Curcumin induces differentiation of embryonic stem cells through possible modulation of nitric oxide-cyclic GMP pathway

Curcumin, an active ingredient of dietary spice used in curry, has been shown to exhibit anti-oxidant, anti-inflammatory and anti-proliferative properties. Using EB directed differentiation protocol of H-9 human embryonic stem (ES) cells; we evaluated the effect of curcumin (0-20 μmol/L) in enhancing such differentiation. Our results using real time PCR, western blotting and immunostaining demonstrated that curcumin significantly increased the gene expression and protein levels of cardiac specific transcription factor NKx2.5, cardiac troponin I, myosin heavy chain, and endothelial nitric oxide synthase during ES cell differentiation. Furthermore, an NO donor enhanced the curcumin-mediated induction of NKx2.5 and other cardiac specific proteins. Incubation of cells with curcumin led to a dose dependent increase in intracellular nitrite to the same extent as giving an authentic NO donor. Functional assay for second messenger(s) cyclic AMP (cAMP) and cyclic GMP (cGMP) revealed that continuous presence of curcumin in differentiated cells induced a decrease in the baseline levels of cAMP but it significantly elevated baseline contents of cGMP. Curcumin addition to a cell free assay significantly suppressed cAMP and cGMP degradation in the extracts while long term treatment of intact cells with curcumin increased the rates of cAMP and cGMP degradation suggesting that this might be due to direct suppression of some cyclic nucleotide-degrading enzyme (phosphodiesterase) by curcumin. These studies demonstrate that polyphenol curcumin may be involved in differentiation of ES cells partly due to manipulation of nitric oxide signaling.

Puerarin enhances superoxide dismutase activity and inhibits RAGE and VEGF expression in retinas of STZ-induced early diabetic rats

OBJECTIVE@#To investigate the effects of puerarin on the activity of superoxide dismutase (SOD), and expressions of advanced glycation end-product (AGE) receptor (RAGE) and vascular endothelial growth factor (VEGF) in retinas of streptozotocin (STZ)-induced early diabetic rats.@*METHODS@#Diabetic rat models were established by inducing diabetes via intra-peritoneal injection of STZ. Rats were randomly divided into normal (control), diabetic (DM), and DM+ puerarin groups. After intra-gastric administration of puerarin (500 mg/kg/day for 4 weeks), levels of SOD and malondialdehyde (MDA) were determined in serum and retina. mRNA and protein expression levels of RAGE and VEGF in retinas were determined by real-time polymerase chain reaction (RT-PCR) (mRNA) and Western blot analysis (protein levels).@*RESULTS@#There was significantly lower SOD activity and significantly higher MDA in serum and retinas of the DM group compared with the two other groups (P<0.05). After treatment with puerarin, SOD activity increased and MDA content decreased in this group (P<0.05). mRNA and protein expression levels of RAGE and VEGF in the DM group were significantly higher than those of the other groups (P<0.05), and decreased after puerarin treatment (P<0.05).@*CONCLUSIONS@#Puerarin is able to enhance SOD activity, and inhibit RAGE and VEGF expressions in retinas of STZ-induced early diabetic rats.

Comparative study on production of a-Amylase from Bacillus licheniformis strains

Alpha amylase (α-1, 4-glucan-glucanhydrolase, EC 3.2.1.1), an extracellular enzyme, degrades α, 1-4 glucosidic linkages of starch and related substrates in an endo-fashion producing oligosaccharides including maltose, glucose and alpha limit dextrin (7). The present study deals with the production and comparative study of production of α-amylase from two strains of Bacillus licheniformis, MTCC 2617 and 2618, by using four different substrates, starch, rice, wheat and ragi powder as carbon source by submerged fermentation. The effect of varying pH and incubation temperature, activator, inhibitor, and substrate concentration was investigated on the activity of α-amylase produced by MTCC strain 2618. The results shows that the production of the α-amylase by the B.licheniformis strain MTCC 2618, using four different substrates were found to be maximum (Starch 3.64 IU/ml/minutes, Rice powder 2.93 IU/ml/minutes, Wheat powder 2.67 IU/ml/minutes, Ragi powder 2.36 IU/ml/minutes) on comparing the enzyme production of two strains. It was also observed that the maximum production was found on the 3rd day (i.e. 72 hr) and characterization of crude enzyme revealed that optimum activity was at pH 7 and 37ºC.

Xylanase production by Aspergillus awamori under solid state fermentation conditions on tomato pomace

In this work, tomato pomace, a waste abundantly available in the Mediterranean and other temperate climates agro-food industries, has been used as raw material for the production of some hydrolytic enzymes, including xylanase, exo-polygalacturonase (exo-PG), cellulase (CMCase) and ¥á-amylase. The principal step of the process is the solid state fermentation (SSF) of this residue by Aspergillus awamori. In several laboratory experiments, maximum xylanase and exo-PG activities were measured during the first days of culture, reaching values around 100 and 80 IU/gds (international units of enzyme activity per gram of dried solid), respectively. For CMCase and ¥á-amylase production remained almost constant along fermentation, with average values of 19 and 21.5 IU/gds, respectively. Experiments carried out in a plate-type bioreactor at lab scale showed a clear positive effect of aeration on xylanase and CMCase, while the opposite was observed for exo-PG and ¥á-amylase. In general, xylanase was the enzyme produced in higher levels, thus the optimum conditions for the determination of the enzyme activity was characterized. The xylanase activity shows an optimum pH of 5 and an optimum temperature of 50 ¨¬C. The enzyme is activated by Mg2+, but strongly inhibited by Hg2+ and Cu2+. The enzymatic activity remains quite high if the extract is preserved in a range of pH from 3 to 10 and a temperature between 30 ¨¬C to 40 ¨¬C.

Influence of PP2A activator on proliferation of HL-60 cells and analysis of PP2A activity changes in patients with acute myeloid leukemia / 中国实验血液学杂志

In order to investigate the effect of PP2A activator and PP2A inhibitor on proliferation of HL-60 cells and analyze the changes of PP2A activity in patients with acute myeloid leukemia (AML), HL-60 cells were treated with FTY720 alone or in combination with okadaic acid (OA) for 24 hours in culture. Cell proliferation was assayed with CCK8 kit. In addition, 20 AML patients including de novo AML and relapsed AML were enrolled in this study. The activity of PP2A in the peripheral blood mononuclear cells of patients was assayed with a PP2A Immunoprecipitation Phosphatase Assay Kit, the data were analyzed by software SPSS 16.0. The results indicated that as compared with control group, the proliferation of cells in FTY720 group was obviously inhibited (p < 0.05). The proliferation of cells in FTY720 + OA group was slightly inhibited as compared with the control group, there was no statistical difference (p > 0.05), but there was significant difference between the FTY720 + OA and FTY720 groups (p < 0.05). The activity of PP2A in AML patients (453.67 ± 102.52 pmol phosphate) was obviously lower than that in the normal controls (673.29 ± 96.32 pmol phosphate), there was significant difference between them (p < 0.01). It is concluded that the activation or inhibition of PP2A can affect the proliferation of HL-60 cells in vitro. Compared with healthy individuals, the activity of PP2A in AML patients is obviously lower. PP2A protein playing a key role in the occurrence and development of AML may be valuable for the diagnosis and treatment of AML.